21163326040665 has 32 divisors (see below), whose sum is σ = 37624745894400. Its totient is φ = 11286790675200.

The previous prime is 21163326040631. The next prime is 21163326040667. The reversal of 21163326040665 is 56604062336112.

21163326040665 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 3 + 32 + 604 + 0 + 6 + 6 + 5 = 666.

It is not a de Polignac number, because 21163326040665 - 2²⁷ = 21163191822937 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21163326040665.

It is not an unprimeable number, because it can be changed into a prime (21163326040667) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2673121 + ... + 7033649.

It is an arithmetic number, because the mean of its divisors is an integer number (1175773309200).

Almost surely, 2^{21163326040665} is an apocalyptic number.

It is an amenable number.

21163326040665 is a deficient number, since it is larger than the sum of its proper divisors (16461419853735).

21163326040665 is a wasteful number, since it uses less digits than its factorization.

21163326040665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4396494 (or 4396488 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

Adding to 21163326040665 its reverse (56604062336112), we get a palindrome (77767388376777).

The spelling of 21163326040665 in words is "twenty-one trillion, one hundred sixty-three billion, three hundred twenty-six million, forty thousand, six hundred sixty-five".