1625163121 has 4 divisors (see below), whose sum is σ = 1632451072. Its totient is φ = 1617875172.

The previous prime is 1625163109. The next prime is 1625163139. The reversal of 1625163121 is 1213615261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1213615261 = 17 ⋅71389133.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1625163121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1625163121.

It is not an unprimeable number, because it can be changed into a prime (1625163101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3643641 + ... + 3644086.

It is an arithmetic number, because the mean of its divisors is an integer number (408112768).

Almost surely, 2^1625163121 is an apocalyptic number.

It is an amenable number.

1625163121 is a deficient number, since it is larger than the sum of its proper divisors (7287951).

1625163121 is an equidigital number, since it uses as much as digits as its factorization.

1625163121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7287950.

The product of its digits is 2160, while the sum is 28.

The square root of 1625163121 is about 40313.3119577144. The cubic root of 1625163121 is about 1175.7066812175.

Adding to 1625163121 its reverse (1213615261), we get a palindrome (2838778382).

The spelling of 1625163121 in words is "one billion, six hundred twenty-five million, one hundred sixty-three thousand, one hundred twenty-one".