264139988 has 36 divisors (see below), whose sum is σ = 545109012. Its totient is φ = 111646080.

The previous prime is 264139987. The next prime is 264140029. The reversal of 264139988 is 889931462.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 68923204 + 195216784 = 8302^2 + 13972^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (264139987) 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, 5078 + ... + 23538.

It is an arithmetic number, because the mean of its divisors is an integer number (15141917).

Almost surely, 2^264139988 is an apocalyptic number.

264139988 is a gapful number since it is divisible by the number (28) 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 264139988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (272554506).

264139988 is an abundant number, since it is smaller than the sum of its proper divisors (280969024).

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

264139988 is a wasteful number, since it uses less digits than its factorization.

264139988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18552 (or 18543 counting only the distinct ones).

The product of its digits is 746496, while the sum is 50.

The square root of 264139988 is about 16252.3840712678. The cubic root of 264139988 is about 641.6202339220.

The spelling of 264139988 in words is "two hundred sixty-four million, one hundred thirty-nine thousand, nine hundred eighty-eight".