201021220999955 has 12 divisors (see below), whose sum is σ = 247252514311056. Its totient is φ = 156894611505600.

The previous prime is 201021220999891. The next prime is 201021220999961. The reversal of 201021220999955 is 559999022120102.

It is a happy number.

It is not a de Polignac number, because 201021220999955 - 2⁶ = 201021220999891 is a prime.

It is a super-2 number, since 2×201021220999955² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 201021220999955.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11958422351 + ... + 11958439160.

It is an arithmetic number, because the mean of its divisors is an integer number (20604376192588).

Almost surely, 2^{201021220999955} is an apocalyptic number.

201021220999955 is a deficient number, since it is larger than the sum of its proper divisors (46231293311101).

201021220999955 is an equidigital number, since it uses as much as digits as its factorization.

201021220999955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23916861598 (or 23916861557 counting only the distinct ones).

The product of its (nonzero) digits is 2624400, while the sum is 56.

The spelling of 201021220999955 in words is "two hundred one trillion, twenty-one billion, two hundred twenty million, nine hundred ninety-nine thousand, nine hundred fifty-five".