21341456565251 has 4 divisors (see below), whose sum is σ = 21552758115504. Its totient is φ = 21130155015000.

The previous prime is 21341456565229. The next prime is 21341456565257. The reversal of 21341456565251 is 15256565414312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21341456565251 - 2⁴² = 16943410054147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21341456565251.

It is not an unprimeable number, because it can be changed into a prime (21341456565257) 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, 105650774975 + ... + 105650775176.

It is an arithmetic number, because the mean of its divisors is an integer number (5388189528876).

Almost surely, 2^{21341456565251} is an apocalyptic number.

21341456565251 is a deficient number, since it is larger than the sum of its proper divisors (211301550253).

21341456565251 is a wasteful number, since it uses less digits than its factorization.

21341456565251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211301550252.

The product of its digits is 4320000, while the sum is 50.

The spelling of 21341456565251 in words is "twenty-one trillion, three hundred forty-one billion, four hundred fifty-six million, five hundred sixty-five thousand, two hundred fifty-one".