61566415 has 4 divisors (see below), whose sum is σ = 73879704. Its totient is φ = 49253128.

The previous prime is 61566413. The next prime is 61566433. The reversal of 61566415 is 51466516.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 61566415 - 2¹ = 61566413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61566413) 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, 6156637 + ... + 6156646.

It is an arithmetic number, because the mean of its divisors is an integer number (18469926).

Almost surely, 2^61566415 is an apocalyptic number.

61566415 is a deficient number, since it is larger than the sum of its proper divisors (12313289).

61566415 is a wasteful number, since it uses less digits than its factorization.

61566415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12313288.

The product of its digits is 21600, while the sum is 34.

The square root of 61566415 is about 7846.4268938161. The cubic root of 61566415 is about 394.8643768756.

The spelling of 61566415 in words is "sixty-one million, five hundred sixty-six thousand, four hundred fifteen".