57187661 has 4 divisors (see below), whose sum is σ = 58582524. Its totient is φ = 55792800.

The previous prime is 57187651. The next prime is 57187667. The reversal of 57187661 is 16678175.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27102436 + 30085225 = 5206^2 + 5485^2 .

It is not a de Polignac number, because 57187661 - 2⁶ = 57187597 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 1394821 = 57187661 / (5 + 7 + 1 + 8 + 7 + 6 + 6 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57187667) 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, 697370 + ... + 697451.

It is an arithmetic number, because the mean of its divisors is an integer number (14645631).

Almost surely, 2^57187661 is an apocalyptic number.

It is an amenable number.

57187661 is a deficient number, since it is larger than the sum of its proper divisors (1394863).

57187661 is a wasteful number, since it uses less digits than its factorization.

57187661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1394862.

The product of its digits is 70560, while the sum is 41.

The square root of 57187661 is about 7562.2523761112. The cubic root of 57187661 is about 385.2719975935.

The spelling of 57187661 in words is "fifty-seven million, one hundred eighty-seven thousand, six hundred sixty-one".