61081815 has 16 divisors (see below), whose sum is σ = 99388800. Its totient is φ = 32024352.

The previous prime is 61081807. The next prime is 61081819. The reversal of 61081815 is 51818016.

It is a happy number.

It is not a de Polignac number, because 61081815 - 2³ = 61081807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61081819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33625 + ... + 35394.

It is an arithmetic number, because the mean of its divisors is an integer number (6211800).

Almost surely, 2^61081815 is an apocalyptic number.

61081815 is a deficient number, since it is larger than the sum of its proper divisors (38306985).

61081815 is a wasteful number, since it uses less digits than its factorization.

61081815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69086.

The product of its (nonzero) digits is 1920, while the sum is 30.

The square root of 61081815 is about 7815.4855895203. The cubic root of 61081815 is about 393.8256312265.

The spelling of 61081815 in words is "sixty-one million, eighty-one thousand, eight hundred fifteen".