21236642413 has 4 divisors (see below), whose sum is σ = 24270448480. Its totient is φ = 18202836348.

The previous prime is 21236642407. The next prime is 21236642423. The reversal of 21236642413 is 31424663212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21236642413 - 2¹⁷ = 21236511341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21236642423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1516903023 + ... + 1516903036.

It is an arithmetic number, because the mean of its divisors is an integer number (6067612120).

Almost surely, 2^21236642413 is an apocalyptic number.

It is an amenable number.

21236642413 is a deficient number, since it is larger than the sum of its proper divisors (3033806067).

21236642413 is an equidigital number, since it uses as much as digits as its factorization.

21236642413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3033806066.

The product of its digits is 41472, while the sum is 34.

The spelling of 21236642413 in words is "twenty-one billion, two hundred thirty-six million, six hundred forty-two thousand, four hundred thirteen".