61557505 has 4 divisors (see below), whose sum is σ = 73869012. Its totient is φ = 49246000.

The previous prime is 61557487. The next prime is 61557533. The reversal of 61557505 is 50575516.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19722481 + 41835024 = 4441^2 + 6468^2 .

It is a de Polignac number, because none of the positive numbers 2^k-61557505 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6155746 + ... + 6155755.

It is an arithmetic number, because the mean of its divisors is an integer number (18467253).

Almost surely, 2^61557505 is an apocalyptic number.

It is an amenable number.

61557505 is a deficient number, since it is larger than the sum of its proper divisors (12311507).

61557505 is a wasteful number, since it uses less digits than its factorization.

61557505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12311506.

The product of its (nonzero) digits is 26250, while the sum is 34.

The square root of 61557505 is about 7845.8590989133. The cubic root of 61557505 is about 394.8453274673.

The spelling of 61557505 in words is "sixty-one million, five hundred fifty-seven thousand, five hundred five".