21655404445015 has 64 divisors (see below), whose sum is σ = 31598378173440. Its totient is φ = 14041867069440.

The previous prime is 21655404444997. The next prime is 21655404445033. The reversal of 21655404445015 is 51054440455612.

It is an interprime number because it is at equal distance from previous prime (21655404444997) and next prime (21655404445033).

It is not a de Polignac number, because 21655404445015 - 2¹³ = 21655404436823 is a prime.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 358520797 + ... + 358581193.

It is an arithmetic number, because the mean of its divisors is an integer number (493724658960).

Almost surely, 2^{21655404445015} is an apocalyptic number.

21655404445015 is a deficient number, since it is larger than the sum of its proper divisors (9942973728425).

21655404445015 is a wasteful number, since it uses less digits than its factorization.

21655404445015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80632.

The product of its (nonzero) digits is 1920000, while the sum is 46.

The spelling of 21655404445015 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred four million, four hundred forty-five thousand, fifteen".