20506570451 has 24 divisors (see below), whose sum is σ = 21665972640. Its totient is φ = 19384243200.

The previous prime is 20506570429. The next prime is 20506570457. The reversal of 20506570451 is 15407560502.

It is a de Polignac number, because none of the positive numbers 2^k-20506570451 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506570457) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30470051 + ... + 30470723.

It is an arithmetic number, because the mean of its divisors is an integer number (902748860).

Almost surely, 2^20506570451 is an apocalyptic number.

20506570451 is a deficient number, since it is larger than the sum of its proper divisors (1159402189).

20506570451 is a wasteful number, since it uses less digits than its factorization.

20506570451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007 (or 906 counting only the distinct ones).

The product of its (nonzero) digits is 42000, while the sum is 35.

The spelling of 20506570451 in words is "twenty billion, five hundred six million, five hundred seventy thousand, four hundred fifty-one".