1620725657 has 8 divisors (see below), whose sum is σ = 1626630720. Its totient is φ = 1614829680.

The previous prime is 1620725647. The next prime is 1620725713. The reversal of 1620725657 is 7565270261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1620725657 - 2⁸ = 1620725401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1620725627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 759482 + ... + 761612.

It is an arithmetic number, because the mean of its divisors is an integer number (203328840).

Almost surely, 2^1620725657 is an apocalyptic number.

It is an amenable number.

1620725657 is a deficient number, since it is larger than the sum of its proper divisors (5905063).

1620725657 is a wasteful number, since it uses less digits than its factorization.

1620725657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4543.

The product of its (nonzero) digits is 176400, while the sum is 41.

The square root of 1620725657 is about 40258.2371322938. The cubic root of 1620725657 is about 1174.6356273531.

The spelling of 1620725657 in words is "one billion, six hundred twenty million, seven hundred twenty-five thousand, six hundred fifty-seven".