1620440653 has 8 divisors (see below), whose sum is σ = 1767180800. Its totient is φ = 1476856368.

The previous prime is 1620440617. The next prime is 1620440659. The reversal of 1620440653 is 3560440261.

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

It is not a de Polignac number, because 1620440653 - 2⁹ = 1620440141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620440659) 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, 787893 + ... + 789946.

It is an arithmetic number, because the mean of its divisors is an integer number (220897600).

Almost surely, 2^1620440653 is an apocalyptic number.

1620440653 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1620440653 is a deficient number, since it is larger than the sum of its proper divisors (146740147).

1620440653 is a wasteful number, since it uses less digits than its factorization.

1620440653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1577931.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 1620440653 is about 40254.6972787028. The cubic root of 1620440653 is about 1174.5667702384.

The spelling of 1620440653 in words is "one billion, six hundred twenty million, four hundred forty thousand, six hundred fifty-three".