21264540001 has 4 divisors (see below), whose sum is σ = 21271207104. Its totient is φ = 21257872900.

The previous prime is 21264539969. The next prime is 21264540019. The reversal of 21264540001 is 10004546212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21264540001 - 2⁵ = 21264539969 is a prime.

It is a super-2 number, since 2×21264540001² (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 (21264540091) 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, 3328765 + ... + 3335146.

It is an arithmetic number, because the mean of its divisors is an integer number (5317801776).

Almost surely, 2^21264540001 is an apocalyptic number.

It is an amenable number.

21264540001 is a deficient number, since it is larger than the sum of its proper divisors (6667103).

21264540001 is an equidigital number, since it uses as much as digits as its factorization.

21264540001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6667102.

The product of its (nonzero) digits is 1920, while the sum is 25.

The spelling of 21264540001 in words is "twenty-one billion, two hundred sixty-four million, five hundred forty thousand, one".