2101121990 has 32 divisors (see below), whose sum is σ = 4305229056. Its totient is φ = 730824160.

The previous prime is 2101121959. The next prime is 2101122017. The reversal of 2101121990 is 991211012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 412712 + ... + 417771.

It is an arithmetic number, because the mean of its divisors is an integer number (134538408).

Almost surely, 2^2101121990 is an apocalyptic number.

2101121990 is an abundant number, since it is smaller than the sum of its proper divisors (2204107066).

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

2101121990 is a wasteful number, since it uses less digits than its factorization.

2101121990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830524.

The product of its (nonzero) digits is 324, while the sum is 26.

The square root of 2101121990 is about 45837.9972293729. The cubic root of 2101121990 is about 1280.8071874016.

The spelling of 2101121990 in words is "two billion, one hundred one million, one hundred twenty-one thousand, nine hundred ninety".