21318025407 has 24 divisors (see below), whose sum is σ = 33086097792. Its totient is φ = 12173842800.

The previous prime is 21318025369. The next prime is 21318025427. The reversal of 21318025407 is 70452081312.

It is not a de Polignac number, because 21318025407 - 2¹² = 21318021311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21318025427) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 184782 + ... + 277092.

It is an arithmetic number, because the mean of its divisors is an integer number (1378587408).

Almost surely, 2^21318025407 is an apocalyptic number.

21318025407 is a deficient number, since it is larger than the sum of its proper divisors (11768072385).

21318025407 is a wasteful number, since it uses less digits than its factorization.

21318025407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93899 (or 93892 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The spelling of 21318025407 in words is "twenty-one billion, three hundred eighteen million, twenty-five thousand, four hundred seven".