21365334041251 has 16 divisors (see below), whose sum is σ = 22723462742400. Its totient is φ = 20030601846528.

The previous prime is 21365334041237. The next prime is 21365334041263. The reversal of 21365334041251 is 15214043356312.

It is a cyclic number.

It is not a de Polignac number, because 21365334041251 - 2¹⁵ = 21365334008483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21365334048251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23368560 + ... + 24265618.

It is an arithmetic number, because the mean of its divisors is an integer number (1420216421400).

Almost surely, 2^{21365334041251} is an apocalyptic number.

21365334041251 is a deficient number, since it is larger than the sum of its proper divisors (1358128701149).

21365334041251 is a wasteful number, since it uses less digits than its factorization.

21365334041251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910098.

The product of its (nonzero) digits is 259200, while the sum is 40.

Adding to 21365334041251 its reverse (15214043356312), we get a palindrome (36579377397563).

The spelling of 21365334041251 in words is "twenty-one trillion, three hundred sixty-five billion, three hundred thirty-four million, forty-one thousand, two hundred fifty-one".