21665826370619 has 16 divisors (see below), whose sum is σ = 21754982236416. Its totient is φ = 21576877264800.

The previous prime is 21665826370553. The next prime is 21665826370681. The reversal of 21665826370619 is 91607362856612.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21665826370619 is a prime.

It is a super-2 number, since 2×21665826370619² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21665826370519) 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, 1089217664 + ... + 1089237554.

It is an arithmetic number, because the mean of its divisors is an integer number (1359686389776).

Almost surely, 2^{21665826370619} is an apocalyptic number.

21665826370619 is a deficient number, since it is larger than the sum of its proper divisors (89155865797).

21665826370619 is a wasteful number, since it uses less digits than its factorization.

21665826370619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24866.

The product of its (nonzero) digits is 39191040, while the sum is 62.

The spelling of 21665826370619 in words is "twenty-one trillion, six hundred sixty-five billion, eight hundred twenty-six million, three hundred seventy thousand, six hundred nineteen".