21450763501 has 4 divisors (see below), whose sum is σ = 21451828732. Its totient is φ = 21449698272.

The previous prime is 21450763487. The next prime is 21450763513. The reversal of 21450763501 is 10536705412.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5176658601 + 16274104900 = 71949^2 + 127570^2 .

It is a cyclic number.

It is not a de Polignac number, because 21450763501 - 2²⁷ = 21316545773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450763531) 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, 501816 + ... + 542881.

It is an arithmetic number, because the mean of its divisors is an integer number (5362957183).

Almost surely, 2^21450763501 is an apocalyptic number.

It is an amenable number.

21450763501 is a deficient number, since it is larger than the sum of its proper divisors (1065231).

21450763501 is a wasteful number, since it uses less digits than its factorization.

21450763501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065230.

The product of its (nonzero) digits is 25200, while the sum is 34.

The spelling of 21450763501 in words is "twenty-one billion, four hundred fifty million, seven hundred sixty-three thousand, five hundred one".