210121010021999 has 16 divisors (see below), whose sum is σ = 220242540951552. Its totient is φ = 200081653456608.

The previous prime is 210121010021959. The next prime is 210121010022019. The reversal of 210121010021999 is 999120010121012.

It is a cyclic number.

It is not a de Polignac number, because 210121010021999 - 2¹² = 210121010017903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210121010021929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 553347269 + ... + 553726865.

It is an arithmetic number, because the mean of its divisors is an integer number (13765158809472).

Almost surely, 2^{210121010021999} is an apocalyptic number.

210121010021999 is a deficient number, since it is larger than the sum of its proper divisors (10121530929553).

210121010021999 is a wasteful number, since it uses less digits than its factorization.

210121010021999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487766.

The product of its (nonzero) digits is 5832, while the sum is 38.

The spelling of 210121010021999 in words is "two hundred ten trillion, one hundred twenty-one billion, ten million, twenty-one thousand, nine hundred ninety-nine".