155431920 has 120 divisors (see below), whose sum is σ = 560548944. Its totient is φ = 35524608.

The previous prime is 155431897. The next prime is 155431921. The reversal of 155431920 is 29134551.

155431920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155431921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5152 + ... + 18368.

Almost surely, 2^155431920 is an apocalyptic number.

155431920 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 155431920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280274472).

155431920 is an abundant number, since it is smaller than the sum of its proper divisors (405117024).

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

155431920 is a wasteful number, since it uses less digits than its factorization.

155431920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13247 (or 13234 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 155431920 is about 12467.2338551902. The cubic root of 155431920 is about 537.6670272331.

The spelling of 155431920 in words is "one hundred fifty-five million, four hundred thirty-one thousand, nine hundred twenty".