1720021998 has 32 divisors (see below), whose sum is σ = 3455792640. Its totient is φ = 570723840.

The previous prime is 1720021957. The next prime is 1720022033. The reversal of 1720021998 is 8991200271.

It is a congruent number.

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, 2391883 + ... + 2392601.

It is an arithmetic number, because the mean of its divisors is an integer number (107993520).

Almost surely, 2^1720021998 is an apocalyptic number.

1720021998 is an abundant number, since it is smaller than the sum of its proper divisors (1735770642).

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

1720021998 is a wasteful number, since it uses less digits than its factorization.

1720021998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1992.

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 1720021998 is about 41473.1479152475. The cubic root of 1720021998 is about 1198.1503908642.

The spelling of 1720021998 in words is "one billion, seven hundred twenty million, twenty-one thousand, nine hundred ninety-eight".