21161004001465 has 16 divisors (see below), whose sum is σ = 25542132319296. Its totient is φ = 16829534635200.

The previous prime is 21161004001453. The next prime is 21161004001483. The reversal of 21161004001465 is 56410040016112.

It is not a de Polignac number, because 21161004001465 - 2¹⁷ = 21161003870393 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9333130 + ... + 11376700.

It is an arithmetic number, because the mean of its divisors is an integer number (1596383269956).

Almost surely, 2^{21161004001465} is an apocalyptic number.

It is an amenable number.

21161004001465 is a deficient number, since it is larger than the sum of its proper divisors (4381128317831).

21161004001465 is a wasteful number, since it uses less digits than its factorization.

21161004001465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2055720.

The product of its (nonzero) digits is 5760, while the sum is 31.

Adding to 21161004001465 its reverse (56410040016112), we get a palindrome (77571044017577).

The spelling of 21161004001465 in words is "twenty-one trillion, one hundred sixty-one billion, four million, one thousand, four hundred sixty-five".