155724 has 24 divisors (see below), whose sum is σ = 383040. Its totient is φ = 49104.

The previous prime is 155723. The next prime is 155731. The reversal of 155724 is 427551.

155724 = 136² + 137² + ... + 143².

It is a junction number, because it is equal to n+sod(n) for n = 155694 and 155703.

It is not an unprimeable number, because it can be changed into a prime (155723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114 + ... + 569.

It is an arithmetic number, because the mean of its divisors is an integer number (15960).

2¹⁵⁵⁷²⁴ is an apocalyptic number.

It is an amenable number.

155724 is an abundant number, since it is smaller than the sum of its proper divisors (227316).

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

155724 is a wasteful number, since it uses less digits than its factorization.

155724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709 (or 707 counting only the distinct ones).

The product of its digits is 1400, while the sum is 24.

The square root of 155724 is about 394.6188034040. The cubic root of 155724 is about 53.8003602285.

It can be divided in two parts, 15572 and 4, that added together give a triangular number (15576 = T₁₇₆).

The spelling of 155724 in words is "one hundred fifty-five thousand, seven hundred twenty-four".