61661506 has 4 divisors (see below), whose sum is σ = 92492262. Its totient is φ = 30830752.

The previous prime is 61661503. The next prime is 61661513. The reversal of 61661506 is 60516616.

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., 36711481 + 24950025 = 6059^2 + 4995^2 .

It is a super-3 number, since 3×61661506³ (a number of 24 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (61661503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15415375 + ... + 15415378.

Almost surely, 2^61661506 is an apocalyptic number.

61661506 is a deficient number, since it is larger than the sum of its proper divisors (30830756).

61661506 is a wasteful number, since it uses less digits than its factorization.

61661506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30830755.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 61661506 is about 7852.4840655680. The cubic root of 61661506 is about 395.0675652195.

The spelling of 61661506 in words is "sixty-one million, six hundred sixty-one thousand, five hundred six".