21535122215670 has 64 divisors (see below), whose sum is σ = 61104583249920. Its totient is φ = 4752578694528.

The previous prime is 21535122215657. The next prime is 21535122215701. The reversal of 21535122215670 is 7651222153512.

It is a happy number.

It is a super-2 number, since 2×21535122215670² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

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 31 ways as a sum of consecutive naturals, for example, 1768066342 + ... + 1768078521.

It is an arithmetic number, because the mean of its divisors is an integer number (954759113280).

Almost surely, 2^{21535122215670} is an apocalyptic number.

21535122215670 is an abundant number, since it is smaller than the sum of its proper divisors (39569461034250).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21535122215670 is a wasteful number, since it uses less digits than its factorization.

21535122215670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3536144909.

The product of its (nonzero) digits is 252000, while the sum is 42.

The spelling of 21535122215670 in words is "twenty-one trillion, five hundred thirty-five billion, one hundred twenty-two million, two hundred fifteen thousand, six hundred seventy".