1989406464 has 36 divisors (see below), whose sum is σ = 5294724456. Its totient is φ = 663135232.

The previous prime is 1989406421. The next prime is 1989406477. The reversal of 1989406464 is 4646049891.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1294419 + ... + 1295954.

Almost surely, 2^1989406464 is an apocalyptic number.

It is an amenable number.

1989406464 is an abundant number, since it is smaller than the sum of its proper divisors (3305317992).

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

1989406464 is an equidigital number, since it uses as much as digits as its factorization.

1989406464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2590392 (or 2590378 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 51.

The square root of 1989406464 is about 44602.7629637447. The cubic root of 1989406464 is about 1257.6926075709.

The spelling of 1989406464 in words is "one billion, nine hundred eighty-nine million, four hundred six thousand, four hundred sixty-four".