61806638 has 4 divisors (see below), whose sum is σ = 92709960. Its totient is φ = 30903318.

The previous prime is 61806623. The next prime is 61806643. The reversal of 61806638 is 83660816.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15451658 + ... + 15451661.

It is an arithmetic number, because the mean of its divisors is an integer number (23177490).

Almost surely, 2^61806638 is an apocalyptic number.

61806638 is a deficient number, since it is larger than the sum of its proper divisors (30903322).

61806638 is a wasteful number, since it uses less digits than its factorization.

61806638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30903321.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 61806638 is about 7861.7197864081. The cubic root of 61806638 is about 395.3772777337.

The spelling of 61806638 in words is "sixty-one million, eight hundred six thousand, six hundred thirty-eight".