61817865 has 32 divisors (see below), whose sum is σ = 105494400. Its totient is φ = 30802944.

The previous prime is 61817857. The next prime is 61817869. The reversal of 61817865 is 56871816.

It is not a de Polignac number, because 61817865 - 2³ = 61817857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61817869) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37182 + ... + 38808.

It is an arithmetic number, because the mean of its divisors is an integer number (3296700).

Almost surely, 2^61817865 is an apocalyptic number.

It is an amenable number.

61817865 is a deficient number, since it is larger than the sum of its proper divisors (43676535).

61817865 is a wasteful number, since it uses less digits than its factorization.

61817865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1801.

The product of its digits is 80640, while the sum is 42.

The square root of 61817865 is about 7862.4337835050. The cubic root of 61817865 is about 395.4012160036.

The spelling of 61817865 in words is "sixty-one million, eight hundred seventeen thousand, eight hundred sixty-five".