61515655 has 4 divisors (see below), whose sum is σ = 73818792. Its totient is φ = 49212520.

The previous prime is 61515653. The next prime is 61515659. The reversal of 61515655 is 55651516.

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

It is not a de Polignac number, because 61515655 - 2¹ = 61515653 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61515655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61515653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6151561 + ... + 6151570.

It is an arithmetic number, because the mean of its divisors is an integer number (18454698).

Almost surely, 2^61515655 is an apocalyptic number.

61515655 is a deficient number, since it is larger than the sum of its proper divisors (12303137).

61515655 is a wasteful number, since it uses less digits than its factorization.

61515655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12303136.

The product of its digits is 22500, while the sum is 34.

The square root of 61515655 is about 7843.1916335125. The cubic root of 61515655 is about 394.7558283718.

The spelling of 61515655 in words is "sixty-one million, five hundred fifteen thousand, six hundred fifty-five".