155638992 has 20 divisors (see below), whose sum is σ = 402067520. Its totient is φ = 51879648.

The previous prime is 155638981. The next prime is 155639009. The reversal of 155638992 is 299836551.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48), and also a Moran number because the ratio is a prime number: 3242479 = 155638992 / (1 + 5 + 5 + 6 + 3 + 8 + 9 + 9 + 2).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1621192 + ... + 1621287.

It is an arithmetic number, because the mean of its divisors is an integer number (20103376).

Almost surely, 2^155638992 is an apocalyptic number.

155638992 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

155638992 is an abundant number, since it is smaller than the sum of its proper divisors (246428528).

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

155638992 is a wasteful number, since it uses less digits than its factorization.

155638992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3242490 (or 3242484 counting only the distinct ones).

The product of its digits is 583200, while the sum is 48.

The square root of 155638992 is about 12475.5357399993. The cubic root of 155638992 is about 537.9056877377.

The spelling of 155638992 in words is "one hundred fifty-five million, six hundred thirty-eight thousand, nine hundred ninety-two".