2156634665655 has 32 divisors (see below), whose sum is σ = 3483641965824. Its totient is φ = 1139201124096.

The previous prime is 2156634665651. The next prime is 2156634665699. The reversal of 2156634665655 is 5565664366512.

It is a happy number.

It is not a de Polignac number, because 2156634665655 - 2² = 2156634665651 is a prime.

It is a super-2 number, since 2×2156634665655² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156634665651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7150179 + ... + 7445691.

It is an arithmetic number, because the mean of its divisors is an integer number (108863811432).

Almost surely, 2^{2156634665655} is an apocalyptic number.

2156634665655 is a deficient number, since it is larger than the sum of its proper divisors (1327007300169).

2156634665655 is a wasteful number, since it uses less digits than its factorization.

2156634665655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300175.

The product of its digits is 116640000, while the sum is 60.

The spelling of 2156634665655 in words is "two trillion, one hundred fifty-six billion, six hundred thirty-four million, six hundred sixty-five thousand, six hundred fifty-five".