21661042632502 has 32 divisors (see below), whose sum is σ = 39989999960064. Its totient is φ = 8569121652000.

The previous prime is 21661042632499. The next prime is 21661042632503. The reversal of 21661042632502 is 20523624016612.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661042632503) 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 15 ways as a sum of consecutive naturals, for example, 20664427 + ... + 21687337.

It is an arithmetic number, because the mean of its divisors is an integer number (1249687498752).

Almost surely, 2^{21661042632502} is an apocalyptic number.

21661042632502 is a deficient number, since it is larger than the sum of its proper divisors (18328957327562).

21661042632502 is a wasteful number, since it uses less digits than its factorization.

21661042632502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139284.

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 21661042632502 in words is "twenty-one trillion, six hundred sixty-one billion, forty-two million, six hundred thirty-two thousand, five hundred two".