21000120999976 has 32 divisors (see below), whose sum is σ = 39464773425000. Its totient is φ = 10476183617536.

The previous prime is 21000120999973. The next prime is 21000121000031. The reversal of 21000120999976 is 67999902100012.

It can be written as a sum of positive squares in 4 ways, for example, as 12025123611076 + 8974997388900 = 3467726^2 + 2995830^2 .

It is not an unprimeable number, because it can be changed into a prime (21000120999973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83557350 + ... + 83808298.

Almost surely, 2^{21000120999976} is an apocalyptic number.

It is an amenable number.

21000120999976 is a deficient number, since it is larger than the sum of its proper divisors (18464652425024).

21000120999976 is a wasteful number, since it uses less digits than its factorization.

21000120999976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274701 (or 274697 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 55.

The spelling of 21000120999976 in words is "twenty-one trillion, one hundred twenty million, nine hundred ninety-nine thousand, nine hundred seventy-six".