61812557 has 4 divisors (see below), whose sum is σ = 61895616. Its totient is φ = 61729500.

The previous prime is 61812539. The next prime is 61812563. The reversal of 61812557 is 75521816.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61812557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61815557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40403 + ... + 41904.

It is an arithmetic number, because the mean of its divisors is an integer number (15473904).

Almost surely, 2^61812557 is an apocalyptic number.

It is an amenable number.

61812557 is a deficient number, since it is larger than the sum of its proper divisors (83059).

61812557 is an equidigital number, since it uses as much as digits as its factorization.

61812557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83058.

The product of its digits is 16800, while the sum is 35.

The square root of 61812557 is about 7862.0962217465. The cubic root of 61812557 is about 395.3898986186.

The spelling of 61812557 in words is "sixty-one million, eight hundred twelve thousand, five hundred fifty-seven".