655138944 has 96 divisors (see below), whose sum is σ = 1890464940. Its totient is φ = 217774080.

The previous prime is 655138933. The next prime is 655138949. The reversal of 655138944 is 449831556.

655138944 is a `hidden beast` number, since 6 + 551 + 3 + 8 + 94 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 629006400 + 26132544 = 25080^2 + 5112^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-4 number, since 4×655138944⁴ (a number of 36 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 655138944.

It is not an unprimeable number, because it can be changed into a prime (655138949) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 641154 + ... + 642174.

Almost surely, 2^655138944 is an apocalyptic number.

655138944 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 655138944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (945232470).

655138944 is an abundant number, since it is smaller than the sum of its proper divisors (1235325996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

655138944 is a wasteful number, since it uses less digits than its factorization.

655138944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1598 (or 1583 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 655138944 is about 25595.6821358603. The cubic root of 655138944 is about 868.5159638438.

The spelling of 655138944 in words is "six hundred fifty-five million, one hundred thirty-eight thousand, nine hundred forty-four".