21312231001 has 4 divisors (see below), whose sum is σ = 21320095104. Its totient is φ = 21304366900.

The previous prime is 21312230971. The next prime is 21312231029. The reversal of 21312231001 is 10013221312.

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 21312231001 - 2⁵ = 21312230969 is a prime.

It is a super-2 number, since 2×21312231001² (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 (21312231041) 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, 3927985 + ... + 3933406.

It is an arithmetic number, because the mean of its divisors is an integer number (5330023776).

Almost surely, 2^21312231001 is an apocalyptic number.

It is an amenable number.

21312231001 is a deficient number, since it is larger than the sum of its proper divisors (7864103).

21312231001 is an equidigital number, since it uses as much as digits as its factorization.

21312231001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7864102.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21312231001 its reverse (10013221312), we get a palindrome (31325452313).

The spelling of 21312231001 in words is "twenty-one billion, three hundred twelve million, two hundred thirty-one thousand, one".