19900845 has 24 divisors (see below), whose sum is σ = 34889400. Its totient is φ = 10492416.

The previous prime is 19900831. The next prime is 19900891. The reversal of 19900845 is 54800991.

It can be written as a sum of positive squares in 4 ways, for example, as 324 + 19900521 = 18^2 + 4461^2 .

It is not a de Polignac number, because 19900845 - 2⁶ = 19900781 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1521 + ... + 6489.

It is an arithmetic number, because the mean of its divisors is an integer number (1453725).

Almost surely, 2^19900845 is an apocalyptic number.

19900845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19900845 is a deficient number, since it is larger than the sum of its proper divisors (14988555).

19900845 is a wasteful number, since it uses less digits than its factorization.

19900845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5069 (or 5066 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 19900845 is about 4461.0363145798. The cubic root of 19900845 is about 270.9924381636.

The spelling of 19900845 in words is "nineteen million, nine hundred thousand, eight hundred forty-five".