21017413121 has 4 divisors (see below), whose sum is σ = 21110001072. Its totient is φ = 20924825172.

The previous prime is 21017413117. The next prime is 21017413163. The reversal of 21017413121 is 12131471012.

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 21017413121 - 2² = 21017413117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21017413171) 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, 46293635 + ... + 46294088.

It is an arithmetic number, because the mean of its divisors is an integer number (5277500268).

Almost surely, 2^21017413121 is an apocalyptic number.

It is an amenable number.

21017413121 is a deficient number, since it is larger than the sum of its proper divisors (92587951).

21017413121 is an equidigital number, since it uses as much as digits as its factorization.

21017413121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92587950.

The product of its (nonzero) digits is 336, while the sum is 23.

Adding to 21017413121 its reverse (12131471012), we get a palindrome (33148884133).

The spelling of 21017413121 in words is "twenty-one billion, seventeen million, four hundred thirteen thousand, one hundred twenty-one".