61557243 has 8 divisors (see below), whose sum is σ = 89537856. Its totient is φ = 37307400.

The previous prime is 61557211. The next prime is 61557247. The reversal of 61557243 is 34275516.

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

It is not a de Polignac number, because 61557243 - 2⁵ = 61557211 is a prime.

It is a super-2 number, since 2×61557243² = 7578588331522098, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 1865371 = 61557243 / (6 + 1 + 5 + 5 + 7 + 2 + 4 + 3).

It is not an unprimeable number, because it can be changed into a prime (61557247) 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 7 ways as a sum of consecutive naturals, for example, 932653 + ... + 932718.

It is an arithmetic number, because the mean of its divisors is an integer number (11192232).

Almost surely, 2^61557243 is an apocalyptic number.

61557243 is a deficient number, since it is larger than the sum of its proper divisors (27980613).

61557243 is a wasteful number, since it uses less digits than its factorization.

61557243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1865385.

The product of its digits is 25200, while the sum is 33.

The square root of 61557243 is about 7845.8424021898. The cubic root of 61557243 is about 394.8447672885.

The spelling of 61557243 in words is "sixty-one million, five hundred fifty-seven thousand, two hundred forty-three".