19802540090 has 16 divisors (see below), whose sum is σ = 36873695880. Its totient is φ = 7647877440.

The previous prime is 19802540089. The next prime is 19802540099. The reversal of 19802540090 is 9004520891.

It can be written as a sum of positive squares in 4 ways, for example, as 13609322281 + 6193217809 = 116659^2 + 78697^2 .

It is not an unprimeable number, because it can be changed into a prime (19802540099) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34142021 + ... + 34142600.

Almost surely, 2^19802540090 is an apocalyptic number.

19802540090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19802540090 is a deficient number, since it is larger than the sum of its proper divisors (17071155790).

19802540090 is a wasteful number, since it uses less digits than its factorization.

19802540090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68284657.

The product of its (nonzero) digits is 25920, while the sum is 38.

The spelling of 19802540090 in words is "nineteen billion, eight hundred two million, five hundred forty thousand, ninety".