1620432725 has 6 divisors (see below), whose sum is σ = 2009336610. Its totient is φ = 1296346160.

The previous prime is 1620432719. The next prime is 1620432767. The reversal of 1620432725 is 5272340261.

It can be written as a sum of positive squares in 3 ways, for example, as 324936676 + 1295496049 = 18026^2 + 35993^2 .

It is not a de Polignac number, because 1620432725 - 2⁶ = 1620432661 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1620432691 and 1620432700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 32408630 + ... + 32408679.

It is an arithmetic number, because the mean of its divisors is an integer number (334889435).

Almost surely, 2^1620432725 is an apocalyptic number.

It is an amenable number.

1620432725 is a deficient number, since it is larger than the sum of its proper divisors (388903885).

1620432725 is an equidigital number, since it uses as much as digits as its factorization.

1620432725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64817319 (or 64817314 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 1620432725 is about 40254.5988056023. The cubic root of 1620432725 is about 1174.5648547140.

Adding to 1620432725 its reverse (5272340261), we get a palindrome (6892772986).

The spelling of 1620432725 in words is "one billion, six hundred twenty million, four hundred thirty-two thousand, seven hundred twenty-five".