20520729531 has 6 divisors (see below), whose sum is σ = 29641053780. Its totient is φ = 13680486348.

The previous prime is 20520729511. The next prime is 20520729553. The reversal of 20520729531 is 13592702502.

20520729531 is a `hidden beast` number, since 2 + 0 + 52 + 0 + 72 + 9 + 531 = 666.

It is not a de Polignac number, because 20520729531 - 2¹⁹ = 20520205243 is a prime.

It is a super-2 number, since 2×20520729531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20520729511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1140040521 + ... + 1140040538.

It is an arithmetic number, because the mean of its divisors is an integer number (4940175630).

Almost surely, 2^20520729531 is an apocalyptic number.

20520729531 is a deficient number, since it is larger than the sum of its proper divisors (9120324249).

20520729531 is a wasteful number, since it uses less digits than its factorization.

20520729531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2280081065 (or 2280081062 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The spelling of 20520729531 in words is "twenty billion, five hundred twenty million, seven hundred twenty-nine thousand, five hundred thirty-one".