21403635613 has 16 divisors (see below), whose sum is σ = 23228006256. Its totient is φ = 19642613760.

The previous prime is 21403635607. The next prime is 21403635637. The reversal of 21403635613 is 31653630412.

It can be written as a sum of positive squares in 8 ways, for example, as 4473201924 + 16930433689 = 66882^2 + 130117^2 .

It is a cyclic number.

It is not a de Polignac number, because 21403635613 - 2²¹ = 21401538461 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 (21403635313) 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, 1465495 + ... + 1480027.

It is an arithmetic number, because the mean of its divisors is an integer number (1451750391).

Almost surely, 2^21403635613 is an apocalyptic number.

It is an amenable number.

21403635613 is a deficient number, since it is larger than the sum of its proper divisors (1824370643).

21403635613 is a wasteful number, since it uses less digits than its factorization.

21403635613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16704.

The product of its (nonzero) digits is 38880, while the sum is 34.

The spelling of 21403635613 in words is "twenty-one billion, four hundred three million, six hundred thirty-five thousand, six hundred thirteen".