21351132143665 has 16 divisors (see below), whose sum is σ = 26970440598720. Its totient is φ = 16181556995520.

The previous prime is 21351132143597. The next prime is 21351132143699. The reversal of 21351132143665 is 56634123115312.

It is not a de Polignac number, because 21351132143665 - 2³³ = 21342542209073 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1954735 + ... + 6820795.

It is an arithmetic number, because the mean of its divisors is an integer number (1685652537420).

Almost surely, 2^{21351132143665} is an apocalyptic number.

It is an amenable number.

21351132143665 is a deficient number, since it is larger than the sum of its proper divisors (5619308455055).

21351132143665 is a wasteful number, since it uses less digits than its factorization.

21351132143665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4912272.

The product of its digits is 388800, while the sum is 43.

Adding to 21351132143665 its reverse (56634123115312), we get a palindrome (77985255258977).

The spelling of 21351132143665 in words is "twenty-one trillion, three hundred fifty-one billion, one hundred thirty-two million, one hundred forty-three thousand, six hundred sixty-five".