19891206490 has 16 divisors (see below), whose sum is σ = 37910299752. Its totient is φ = 7488454144.

The previous prime is 19891206479. The next prime is 19891206509. The reversal of 19891206490 is 9460219891.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18246336241 + 1644870249 = 135079^2 + 40557^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58503379 + ... + 58503718.

Almost surely, 2^19891206490 is an apocalyptic number.

19891206490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19891206490 is a deficient number, since it is larger than the sum of its proper divisors (18019093262).

19891206490 is a wasteful number, since it uses less digits than its factorization.

19891206490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117007121.

The product of its (nonzero) digits is 279936, while the sum is 49.

The spelling of 19891206490 in words is "nineteen billion, eight hundred ninety-one million, two hundred six thousand, four hundred ninety".