61557 has 12 divisors (see below), whose sum is σ = 88416. Its totient is φ = 38080.

The previous prime is 61553. The next prime is 61559. The reversal of 61557 is 75516.

It is not a de Polignac number, because 61557 - 2² = 61553 is a prime.

61557 is a lucky number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 832 + ... + 902.

It is an arithmetic number, because the mean of its divisors is an integer number (7368).

2⁶¹⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

61557 is a deficient number, since it is larger than the sum of its proper divisors (26859).

61557 is a wasteful number, since it uses less digits than its factorization.

61557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108 (or 91 counting only the distinct ones).

The product of its digits is 1050, while the sum is 24.

The square root of 61557 is about 248.1068318285. The cubic root of 61557 is about 39.4844247732.

The spelling of 61557 in words is "sixty-one thousand, five hundred fifty-seven".