21997902413655 has 24 divisors (see below), whose sum is σ = 43576797162912. Its totient is φ = 10056183960384.

The previous prime is 21997902413611. The next prime is 21997902413677. The reversal of 21997902413655 is 55631420979912.

21997902413655 is a `hidden beast` number, since 2 + 1 + 99 + 79 + 0 + 2 + 413 + 65 + 5 = 666.

It is not a de Polignac number, because 21997902413655 - 2⁹ = 21997902413143 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 21997902413592 and 21997902413601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34917305104 + ... + 34917305733.

It is an arithmetic number, because the mean of its divisors is an integer number (1815699881788).

Almost surely, 2^{21997902413655} is an apocalyptic number.

21997902413655 is a deficient number, since it is larger than the sum of its proper divisors (21578894749257).

21997902413655 is a wasteful number, since it uses less digits than its factorization.

21997902413655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69834610855 (or 69834610852 counting only the distinct ones).

The product of its (nonzero) digits is 36741600, while the sum is 63.

The spelling of 21997902413655 in words is "twenty-one trillion, nine hundred ninety-seven billion, nine hundred two million, four hundred thirteen thousand, six hundred fifty-five".