1625657557 has 4 divisors (see below), whose sum is σ = 1626234220. Its totient is φ = 1625080896.

The previous prime is 1625657533. The next prime is 1625657581. The reversal of 1625657557 is 7557565261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7557565261 = 26021 ⋅290441.

It is an interprime number because it is at equal distance from previous prime (1625657533) and next prime (1625657581).

It can be written as a sum of positive squares in 2 ways, for example, as 324324081 + 1301333476 = 18009^2 + 36074^2 .

It is a cyclic number.

It is not a de Polignac number, because 1625657557 - 2¹¹ = 1625655509 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 1625657557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1625657597) 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, 284082 + ... + 289747.

It is an arithmetic number, because the mean of its divisors is an integer number (406558555).

Almost surely, 2^1625657557 is an apocalyptic number.

It is an amenable number.

1625657557 is a deficient number, since it is larger than the sum of its proper divisors (576663).

1625657557 is an equidigital number, since it uses as much as digits as its factorization.

1625657557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576662.

The product of its digits is 2205000, while the sum is 49.

The square root of 1625657557 is about 40319.4439073755. The cubic root of 1625657557 is about 1175.8259005867.

The spelling of 1625657557 in words is "one billion, six hundred twenty-five million, six hundred fifty-seven thousand, five hundred fifty-seven".