20747531 has 12 divisors (see below), whose sum is σ = 25555608. Its totient is φ = 16736832.

The previous prime is 20747513. The next prime is 20747537. The reversal of 20747531 is 13574702.

It is not a de Polignac number, because 20747531 - 2¹⁰ = 20746507 is a prime.

It is a super-2 number, since 2×20747531² = 860920085191922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20747494 and 20747503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20747537) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11621 + ... + 13286.

It is an arithmetic number, because the mean of its divisors is an integer number (2129634).

Almost surely, 2^20747531 is an apocalyptic number.

20747531 is a deficient number, since it is larger than the sum of its proper divisors (4808077).

20747531 is a wasteful number, since it uses less digits than its factorization.

20747531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24938 (or 24931 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 20747531 is about 4554.9457735521. The cubic root of 20747531 is about 274.7823335444.

The spelling of 20747531 in words is "twenty million, seven hundred forty-seven thousand, five hundred thirty-one".