1657001661 has 8 divisors (see below), whose sum is σ = 2524954944. Its totient is φ = 946858080.

The previous prime is 1657001629. The next prime is 1657001683. The reversal of 1657001661 is 1661007561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1657001661 - 2⁵ = 1657001629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1657001561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39452400 + ... + 39452441.

It is an arithmetic number, because the mean of its divisors is an integer number (315619368).

Almost surely, 2^1657001661 is an apocalyptic number.

It is an amenable number.

1657001661 is a deficient number, since it is larger than the sum of its proper divisors (867953283).

1657001661 is an equidigital number, since it uses as much as digits as its factorization.

1657001661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78904851.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 1657001661 is about 40706.2852763551. The cubic root of 1657001661 is about 1183.3348308033.

The spelling of 1657001661 in words is "one billion, six hundred fifty-seven million, one thousand, six hundred sixty-one".