61566638 has 12 divisors (see below), whose sum is σ = 107427672. Its totient is φ = 26385660.

The previous prime is 61566613. The next prime is 61566643. The reversal of 61566638 is 83666516.

It is a junction number, because it is equal to n+sod(n) for n = 61566595 and 61566604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 314018 + ... + 314213.

It is an arithmetic number, because the mean of its divisors is an integer number (8952306).

Almost surely, 2^61566638 is an apocalyptic number.

61566638 is a deficient number, since it is larger than the sum of its proper divisors (45861034).

61566638 is a wasteful number, since it uses less digits than its factorization.

61566638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628247 (or 628240 counting only the distinct ones).

The product of its digits is 155520, while the sum is 41.

The square root of 61566638 is about 7846.4411040930. The cubic root of 61566638 is about 394.8648536217.

The spelling of 61566638 in words is "sixty-one million, five hundred sixty-six thousand, six hundred thirty-eight".