21620961377394 has 16 divisors (see below), whose sum is σ = 44057808090432. Its totient is φ = 7071006236528.

The previous prime is 21620961377333. The next prime is 21620961377399. The reversal of 21620961377394 is 49377316902612.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21620961377399) 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 7 ways as a sum of consecutive naturals, for example, 33995221974 + ... + 33995222609.

It is an arithmetic number, because the mean of its divisors is an integer number (2753613005652).

Almost surely, 2^{21620961377394} is an apocalyptic number.

21620961377394 is an abundant number, since it is smaller than the sum of its proper divisors (22436846713038).

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

21620961377394 is a wasteful number, since it uses less digits than its factorization.

21620961377394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67990444641.

The product of its (nonzero) digits is 20575296, while the sum is 60.

The spelling of 21620961377394 in words is "twenty-one trillion, six hundred twenty billion, nine hundred sixty-one million, three hundred seventy-seven thousand, three hundred ninety-four".