21020500451 has 8 divisors (see below), whose sum is σ = 22145891520. Its totient is φ = 19897014312.

The previous prime is 21020500441. The next prime is 21020500463. The reversal of 21020500451 is 15400502012.

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

It is a cyclic number.

It is not a de Polignac number, because 21020500451 - 2²⁶ = 20953391587 is a prime.

It is a super-2 number, since 2×21020500451² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020500411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 453545 + ... + 497738.

It is an arithmetic number, because the mean of its divisors is an integer number (2768236440).

Almost surely, 2^21020500451 is an apocalyptic number.

21020500451 is a deficient number, since it is larger than the sum of its proper divisors (1125391069).

21020500451 is a wasteful number, since it uses less digits than its factorization.

21020500451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 952465.

The product of its (nonzero) digits is 400, while the sum is 20.

The spelling of 21020500451 in words is "twenty-one billion, twenty million, five hundred thousand, four hundred fifty-one".