61812865 has 4 divisors (see below), whose sum is σ = 74175444. Its totient is φ = 49450288.

The previous prime is 61812851. The next prime is 61812899. The reversal of 61812865 is 56821816.

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 17297281 + 44515584 = 4159^2 + 6672^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61812865 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, 6181282 + ... + 6181291.

It is an arithmetic number, because the mean of its divisors is an integer number (18543861).

Almost surely, 2^61812865 is an apocalyptic number.

It is an amenable number.

61812865 is a deficient number, since it is larger than the sum of its proper divisors (12362579).

61812865 is a wasteful number, since it uses less digits than its factorization.

61812865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12362578.

The product of its digits is 23040, while the sum is 37.

The square root of 61812865 is about 7862.1158093735. The cubic root of 61812865 is about 395.3905553346.

The spelling of 61812865 in words is "sixty-one million, eight hundred twelve thousand, eight hundred sixty-five".