21601988993794 has 16 divisors (see below), whose sum is σ = 36100809461376. Its totient is φ = 9610169184400.

The previous prime is 21601988993731. The next prime is 21601988993803. The reversal of 21601988993794 is 49739988910612.

It is a super-2 number, since 2×21601988993794² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21601988993794.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10445835037 + ... + 10445837104.

It is an arithmetic number, because the mean of its divisors is an integer number (2256300591336).

Almost surely, 2^{21601988993794} is an apocalyptic number.

21601988993794 is a deficient number, since it is larger than the sum of its proper divisors (14498820467582).

21601988993794 is a wasteful number, since it uses less digits than its factorization.

21601988993794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20891672201.

The product of its (nonzero) digits is 423263232, while the sum is 76.

The spelling of 21601988993794 in words is "twenty-one trillion, six hundred one billion, nine hundred eighty-eight million, nine hundred ninety-three thousand, seven hundred ninety-four".