21105136413 has 16 divisors (see below), whose sum is σ = 31856811840. Its totient is φ = 13804616592.

The previous prime is 21105136399. The next prime is 21105136457. The reversal of 21105136413 is 31463150112.

It is a happy number.

21105136413 is a `hidden beast` number, since 2 + 1 + 1 + 0 + 5 + 13 + 641 + 3 = 666.

It is not a de Polignac number, because 21105136413 - 2⁴ = 21105136397 is a prime.

It is a super-2 number, since 2×21105136413² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105136313) 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, 7372831 + ... + 7375692.

It is an arithmetic number, because the mean of its divisors is an integer number (1991050740).

Almost surely, 2^21105136413 is an apocalyptic number.

It is an amenable number.

21105136413 is a deficient number, since it is larger than the sum of its proper divisors (10751675427).

21105136413 is a wasteful number, since it uses less digits than its factorization.

21105136413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14748585 (or 14748579 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

Adding to 21105136413 its reverse (31463150112), we get a palindrome (52568286525).

The spelling of 21105136413 in words is "twenty-one billion, one hundred five million, one hundred thirty-six thousand, four hundred thirteen".