61666659 has 12 divisors (see below), whose sum is σ = 89145576. Its totient is φ = 41078112.

The previous prime is 61666651. The next prime is 61666681. The reversal of 61666659 is 95666616.

It is not a de Polignac number, because 61666659 - 2³ = 61666651 is a prime.

It is a super-4 number, since 4×61666659⁴ (a number of 32 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (61666651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15367 + ... + 18959.

It is an arithmetic number, because the mean of its divisors is an integer number (7428798).

Almost surely, 2^61666659 is an apocalyptic number.

61666659 is a deficient number, since it is larger than the sum of its proper divisors (27478917).

61666659 is a wasteful number, since it uses less digits than its factorization.

61666659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5506 (or 5503 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 61666659 is about 7852.8121714453. The cubic root of 61666659 is about 395.0785700672.

The spelling of 61666659 in words is "sixty-one million, six hundred sixty-six thousand, six hundred fifty-nine".