21000002009976 has 192 divisors, whose sum is σ = 64752975612000. Its totient is φ = 6089827000320.

The previous prime is 21000002009953. The next prime is 21000002009983. The reversal of 21000002009976 is 67990020000012.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21000002009976.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1450261 + ... + 6641028.

Almost surely, 2^{21000002009976} is an apocalyptic number.

It is an amenable number.

21000002009976 is an abundant number, since it is smaller than the sum of its proper divisors (43752973602024).

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

21000002009976 is a wasteful number, since it uses less digits than its factorization.

21000002009976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8091454 (or 8091447 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

Adding to 21000002009976 its reverse (67990020000012), we get a palindrome (88990022009988).

The spelling of 21000002009976 in words is "twenty-one trillion, two million, nine thousand, nine hundred seventy-six".