21625531401 has 4 divisors (see below), whose sum is σ = 28834041872. Its totient is φ = 14417020932.

The previous prime is 21625531399. The next prime is 21625531409. The reversal of 21625531401 is 10413552612.

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 not a de Polignac number, because 21625531401 - 2¹ = 21625531399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21625531409) 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, 3604255231 + ... + 3604255236.

It is an arithmetic number, because the mean of its divisors is an integer number (7208510468).

Almost surely, 2^21625531401 is an apocalyptic number.

It is an amenable number.

21625531401 is a deficient number, since it is larger than the sum of its proper divisors (7208510471).

21625531401 is an equidigital number, since it uses as much as digits as its factorization.

21625531401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7208510470.

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21625531401 in words is "twenty-one billion, six hundred twenty-five million, five hundred thirty-one thousand, four hundred one".