1791662640 has 80 divisors (see below), whose sum is σ = 5880882528. Its totient is φ = 449671168.

The previous prime is 1791662599. The next prime is 1791662641. The reversal of 1791662640 is 462661971.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 1791662592 and 1791662601.

It is not an unprimeable number, because it can be changed into a prime (1791662641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 215487 + ... + 223646.

Almost surely, 2^1791662640 is an apocalyptic number.

1791662640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1791662640 is an abundant number, since it is smaller than the sum of its proper divisors (4089219888).

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

1791662640 is a wasteful number, since it uses less digits than its factorization.

1791662640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439166 (or 439160 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 1791662640 is about 42328.0360990207. The cubic root of 1791662640 is about 1214.5593619684.

The spelling of 1791662640 in words is "one billion, seven hundred ninety-one million, six hundred sixty-two thousand, six hundred forty".