61557251 has 8 divisors (see below), whose sum is σ = 70865760. Its totient is φ = 52377408.

The previous prime is 61557247. The next prime is 61557257. The reversal of 61557251 is 15275516.

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

It is a cyclic number.

It is not a de Polignac number, because 61557251 - 2² = 61557247 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61557257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31136 + ... + 33053.

It is an arithmetic number, because the mean of its divisors is an integer number (8858220).

Almost surely, 2^61557251 is an apocalyptic number.

61557251 is a deficient number, since it is larger than the sum of its proper divisors (9308509).

61557251 is a wasteful number, since it uses less digits than its factorization.

61557251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64333.

The product of its digits is 10500, while the sum is 32.

The square root of 61557251 is about 7845.8429120140. The cubic root of 61557251 is about 394.8447843932.

The spelling of 61557251 in words is "sixty-one million, five hundred fifty-seven thousand, two hundred fifty-one".