1001657557 has 4 divisors (see below), whose sum is σ = 1004343340. Its totient is φ = 998971776.

The previous prime is 1001657549. The next prime is 1001657623. The reversal of 1001657557 is 7557561001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7557561001 = 919 ⋅8223679.

It can be written as a sum of positive squares in 2 ways, for example, as 752459761 + 249197796 = 27431^2 + 15786^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001657557 - 2³ = 1001657549 is a prime.

It is a super-2 number, since 2×1001657557² = 2006635722990416498, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001654557) 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, 1342332 + ... + 1343077.

It is an arithmetic number, because the mean of its divisors is an integer number (251085835).

Almost surely, 2^1001657557 is an apocalyptic number.

It is an amenable number.

1001657557 is a deficient number, since it is larger than the sum of its proper divisors (2685783).

1001657557 is an equidigital number, since it uses as much as digits as its factorization.

1001657557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2685782.

The product of its (nonzero) digits is 36750, while the sum is 37.

The square root of 1001657557 is about 31648.9740276047. The cubic root of 1001657557 is about 1000.5522140036.

The spelling of 1001657557 in words is "one billion, one million, six hundred fifty-seven thousand, five hundred fifty-seven".