1938649664 has 56 divisors (see below), whose sum is σ = 4401116928. Its totient is φ = 829992960.

The previous prime is 1938649607. The next prime is 1938649703. The reversal of 1938649664 is 4669468391.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (56).

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, 635984 + ... + 639024.

Almost surely, 2^1938649664 is an apocalyptic number.

1938649664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1938649664 is an abundant number, since it is smaller than the sum of its proper divisors (2462467264).

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

1938649664 is a wasteful number, since it uses less digits than its factorization.

1938649664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4483 (or 4473 counting only the distinct ones).

The product of its digits is 6718464, while the sum is 56.

The square root of 1938649664 is about 44030.0995229400. The cubic root of 1938649664 is about 1246.9042678029.

The spelling of 1938649664 in words is "one billion, nine hundred thirty-eight million, six hundred forty-nine thousand, six hundred sixty-four".