255729138 has 64 divisors (see below), whose sum is σ = 599865600. Its totient is φ = 72648576.

The previous prime is 255729107. The next prime is 255729169. The reversal of 255729138 is 831927552.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (255729107) and next prime (255729169).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 255729138.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 643956 + ... + 644352.

It is an arithmetic number, because the mean of its divisors is an integer number (9372900).

Almost surely, 2^255729138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 255729138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299932800).

255729138 is an abundant number, since it is smaller than the sum of its proper divisors (344136462).

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

255729138 is a wasteful number, since it uses less digits than its factorization.

255729138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736 (or 722 counting only the distinct ones).

The product of its digits is 151200, while the sum is 42.

The square root of 255729138 is about 15991.5333223553. The cubic root of 255729138 is about 634.7364008104.

The spelling of 255729138 in words is "two hundred fifty-five million, seven hundred twenty-nine thousand, one hundred thirty-eight".