19900945 has 16 divisors (see below), whose sum is σ = 24641280. Its totient is φ = 15422400.

The previous prime is 19900927. The next prime is 19900967. The reversal of 19900945 is 54900991.

It is not a de Polignac number, because 19900945 - 2⁷ = 19900817 is a prime.

It is a super-2 number, since 2×19900945² = 792095223786050, which contains 22 as substring.

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, 21196 + ... + 22114.

It is an arithmetic number, because the mean of its divisors is an integer number (1540080).

Almost surely, 2^19900945 is an apocalyptic number.

It is an amenable number.

19900945 is a deficient number, since it is larger than the sum of its proper divisors (4740335).

19900945 is an equidigital number, since it uses as much as digits as its factorization.

19900945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 19900945 is about 4461.0475227238. The cubic root of 19900945 is about 270.9928920672.

The spelling of 19900945 in words is "nineteen million, nine hundred thousand, nine hundred forty-five".