21314121921 has 8 divisors (see below), whose sum is σ = 31576476960. Its totient is φ = 14209414596.

The previous prime is 21314121911. The next prime is 21314121937. The reversal of 21314121921 is 12912141312.

21314121921 is a `hidden beast` number, since 213 + 1 + 412 + 19 + 21 = 666.

It is not a de Polignac number, because 21314121921 - 2¹⁴ = 21314105537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 789411923 = 21314121921 / (2 + 1 + 3 + 1 + 4 + 1 + 2 + 1 + 9 + 2 + 1).

It is not an unprimeable number, because it can be changed into a prime (21314121911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 394705935 + ... + 394705988.

It is an arithmetic number, because the mean of its divisors is an integer number (3947059620).

Almost surely, 2^21314121921 is an apocalyptic number.

It is an amenable number.

21314121921 is a deficient number, since it is larger than the sum of its proper divisors (10262355039).

21314121921 is an equidigital number, since it uses as much as digits as its factorization.

21314121921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789411932 (or 789411926 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The spelling of 21314121921 in words is "twenty-one billion, three hundred fourteen million, one hundred twenty-one thousand, nine hundred twenty-one".