20724531 has 8 divisors (see below), whose sum is σ = 28585680. Its totient is φ = 13339872.

The previous prime is 20724521. The next prime is 20724553. The reversal of 20724531 is 13542702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20724531 - 2⁶ = 20724467 is a prime.

It is a super-2 number, since 2×20724531² = 859012370339922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20724511) 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, 119020 + ... + 119193.

It is an arithmetic number, because the mean of its divisors is an integer number (3573210).

Almost surely, 2^20724531 is an apocalyptic number.

20724531 is a deficient number, since it is larger than the sum of its proper divisors (7861149).

20724531 is a wasteful number, since it uses less digits than its factorization.

20724531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238245.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 20724531 is about 4552.4203452669. The cubic root of 20724531 is about 274.6807579162.

The spelling of 20724531 in words is "twenty million, seven hundred twenty-four thousand, five hundred thirty-one".