61565554 has 4 divisors (see below), whose sum is σ = 92348334. Its totient is φ = 30782776.

The previous prime is 61565527. The next prime is 61565587. The reversal of 61565554 is 45556516.

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

It can be written as a sum of positive squares in only one way, i.e., 43204329 + 18361225 = 6573^2 + 4285^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15391387 + ... + 15391390.

Almost surely, 2^61565554 is an apocalyptic number.

61565554 is a deficient number, since it is larger than the sum of its proper divisors (30782780).

61565554 is a wasteful number, since it uses less digits than its factorization.

61565554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30782779.

The product of its digits is 90000, while the sum is 37.

The square root of 61565554 is about 7846.3720278865. The cubic root of 61565554 is about 394.8625361544.

It can be divided in two parts, 615 and 65554, that multiplied together give a triangular number (40315710 = T₈₉₇₉).

The spelling of 61565554 in words is "sixty-one million, five hundred sixty-five thousand, five hundred fifty-four".