155640531 has 16 divisors (see below), whose sum is σ = 211252608. Its totient is φ = 101904000.

The previous prime is 155640523. The next prime is 155640539. The reversal of 155640531 is 135046551.

155640531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (155640523) and next prime (155640539).

It is not a de Polignac number, because 155640531 - 2³ = 155640523 is a prime.

It is a super-2 number, since 2×155640531² = 48447949779923922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (155640539) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79636 + ... + 81566.

It is an arithmetic number, because the mean of its divisors is an integer number (13203288).

Almost surely, 2^155640531 is an apocalyptic number.

155640531 is a deficient number, since it is larger than the sum of its proper divisors (55612077).

155640531 is a wasteful number, since it uses less digits than its factorization.

155640531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2402.

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 155640531 is about 12475.5974205647. The cubic root of 155640531 is about 537.9074607170.

The spelling of 155640531 in words is "one hundred fifty-five million, six hundred forty thousand, five hundred thirty-one".