155191645440 has 1080 divisors, whose sum is σ = 637898555448. Its totient is φ = 35884892160.

The previous prime is 155191645439. The next prime is 155191645451. The reversal of 155191645440 is 44546191551.

155191645440 is a `hidden beast` number, since 1 + 5 + 5 + 191 + 6 + 454 + 4 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 82447082496 + 72744562944 = 287136^2 + 269712^2 .

It is a tau number, because it is divible by the number of its divisors (1080).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 297872380 + ... + 297872900.

Almost surely, 2^155191645440 is an apocalyptic number.

155191645440 is a gapful number since it is divisible by the number (10) 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 155191645440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318949277724).

155191645440 is an abundant number, since it is smaller than the sum of its proper divisors (482706910008).

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

155191645440 is a wasteful number, since it uses less digits than its factorization.

155191645440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597 (or 561 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 45.

The spelling of 155191645440 in words is "one hundred fifty-five billion, one hundred ninety-one million, six hundred forty-five thousand, four hundred forty".