20501164531 has 4 divisors (see below), whose sum is σ = 20501562064. Its totient is φ = 20500767000.

The previous prime is 20501164529. The next prime is 20501164553. The reversal of 20501164531 is 13546110502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20501164531 - 2¹ = 20501164529 is a prime.

It is a super-2 number, since 2×20501164531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20501164531.

It is not an unprimeable number, because it can be changed into a prime (20501164511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107415 + ... + 229216.

It is an arithmetic number, because the mean of its divisors is an integer number (5125390516).

Almost surely, 2^20501164531 is an apocalyptic number.

20501164531 is a deficient number, since it is larger than the sum of its proper divisors (397533).

20501164531 is an equidigital number, since it uses as much as digits as its factorization.

20501164531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397532.

The product of its (nonzero) digits is 3600, while the sum is 28.

The spelling of 20501164531 in words is "twenty billion, five hundred one million, one hundred sixty-four thousand, five hundred thirty-one".