57213661 has 2 divisors, whose sum is σ = 57213662. Its totient is φ = 57213660.

The previous prime is 57213623. The next prime is 57213679. The reversal of 57213661 is 16631275.

57213661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50552100 + 6661561 = 7110^2 + 2581^2 .

It is a cyclic number.

It is not a de Polignac number, because 57213661 - 2¹³ = 57205469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (57213601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28606830 + 28606831.

It is an arithmetic number, because the mean of its divisors is an integer number (28606831).

Almost surely, 2^57213661 is an apocalyptic number.

It is an amenable number.

57213661 is a deficient number, since it is larger than the sum of its proper divisors (1).

57213661 is an equidigital number, since it uses as much as digits as its factorization.

57213661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 31.

The square root of 57213661 is about 7563.9712453182. The cubic root of 57213661 is about 385.3303758874.

The spelling of 57213661 in words is "fifty-seven million, two hundred thirteen thousand, six hundred sixty-one".