1656672720 has 40 divisors (see below), whose sum is σ = 5135686176. Its totient is φ = 441779328.

The previous prime is 1656672707. The next prime is 1656672733. The reversal of 1656672720 is 272766561.

1656672720 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1656672707) and next prime (1656672733).

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

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, 3451162 + ... + 3451641.

Almost surely, 2^1656672720 is an apocalyptic number.

1656672720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1656672720 is an abundant number, since it is smaller than the sum of its proper divisors (3479013456).

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

1656672720 is a wasteful number, since it uses less digits than its factorization.

1656672720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6902819 (or 6902813 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 42.

The square root of 1656672720 is about 40702.2446555469. The cubic root of 1656672720 is about 1183.2565220701.

The spelling of 1656672720 in words is "one billion, six hundred fifty-six million, six hundred seventy-two thousand, seven hundred twenty".