19721045490 has 32 divisors (see below), whose sum is σ = 47648174400. Its totient is φ = 5223649344.

The previous prime is 19721045429. The next prime is 19721045563. The reversal of 19721045490 is 9454012791.

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, 2201464 + ... + 2210403.

It is an arithmetic number, because the mean of its divisors is an integer number (1489005450).

Almost surely, 2^19721045490 is an apocalyptic number.

19721045490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19721045490 is an abundant number, since it is smaller than the sum of its proper divisors (27927128910).

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

19721045490 is a wasteful number, since it uses less digits than its factorization.

19721045490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4412026.

The product of its (nonzero) digits is 90720, while the sum is 42.

The spelling of 19721045490 in words is "nineteen billion, seven hundred twenty-one million, forty-five thousand, four hundred ninety".