1657725401 has 4 divisors (see below), whose sum is σ = 1657806900. Its totient is φ = 1657643904.

The previous prime is 1657725397. The next prime is 1657725409. The reversal of 1657725401 is 1045277561.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1045277561 = 31 ⋅33718631.

It can be written as a sum of positive squares in 2 ways, for example, as 838392025 + 819333376 = 28955^2 + 28624^2 .

It is a cyclic number.

It is not a de Polignac number, because 1657725401 - 2² = 1657725397 is a prime.

It is a super-2 number, since 2×1657725401² = 5496107010241221602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1657725409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17885 + ... + 60293.

It is an arithmetic number, because the mean of its divisors is an integer number (414451725).

Almost surely, 2^1657725401 is an apocalyptic number.

It is an amenable number.

1657725401 is a deficient number, since it is larger than the sum of its proper divisors (81499).

1657725401 is an equidigital number, since it uses as much as digits as its factorization.

1657725401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81498.

The product of its (nonzero) digits is 58800, while the sum is 38.

The square root of 1657725401 is about 40715.1740878017. The cubic root of 1657725401 is about 1183.5070901542.

The spelling of 1657725401 in words is "one billion, six hundred fifty-seven million, seven hundred twenty-five thousand, four hundred one".