21646152556213 has 8 divisors (see below), whose sum is σ = 21924618632280. Its totient is φ = 21369432349440.

The previous prime is 21646152556183. The next prime is 21646152556243. The reversal of 21646152556213 is 31265525164612.

It is an interprime number because it is at equal distance from previous prime (21646152556183) and next prime (21646152556243).

It can be written as a sum of positive squares in 4 ways, for example, as 961139062129 + 20685013494084 = 980377^2 + 4548078^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21646152556213 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 (21646152556243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 436442368 + ... + 436491961.

It is an arithmetic number, because the mean of its divisors is an integer number (2740577329035).

Almost surely, 2^{21646152556213} is an apocalyptic number.

It is an amenable number.

21646152556213 is a deficient number, since it is larger than the sum of its proper divisors (278466076067).

21646152556213 is a wasteful number, since it uses less digits than its factorization.

21646152556213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872934647.

The product of its digits is 2592000, while the sum is 49.

The spelling of 21646152556213 in words is "twenty-one trillion, six hundred forty-six billion, one hundred fifty-two million, five hundred fifty-six thousand, two hundred thirteen".