215804640055663 has 4 divisors (see below), whose sum is σ = 215970261423088. Its totient is φ = 215639018688240.

The previous prime is 215804640055651. The next prime is 215804640055727. The reversal of 215804640055663 is 366550046408512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215804640055663 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 (215804640055603) 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, 82810681758 + ... + 82810684363.

It is an arithmetic number, because the mean of its divisors is an integer number (53992565355772).

Almost surely, 2^{215804640055663} is an apocalyptic number.

215804640055663 is a deficient number, since it is larger than the sum of its proper divisors (165621367425).

215804640055663 is a wasteful number, since it uses less digits than its factorization.

215804640055663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165621367424.

The product of its (nonzero) digits is 20736000, while the sum is 55.

The spelling of 215804640055663 in words is "two hundred fifteen trillion, eight hundred four billion, six hundred forty million, fifty-five thousand, six hundred sixty-three".