61661977 has 8 divisors (see below), whose sum is σ = 66555720. Its totient is φ = 56789760.

The previous prime is 61661969. The next prime is 61661981. The reversal of 61661977 is 77916616.

It can be written as a sum of positive squares in 4 ways, for example, as 6471936 + 55190041 = 2544^2 + 7429^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61661977 - 2³ = 61661969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61661927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 849 + ... + 11137.

It is an arithmetic number, because the mean of its divisors is an integer number (8319465).

Almost surely, 2^61661977 is an apocalyptic number.

It is an amenable number.

61661977 is a deficient number, since it is larger than the sum of its proper divisors (4893743).

61661977 is a wasteful number, since it uses less digits than its factorization.

61661977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10763.

The product of its digits is 95256, while the sum is 43.

The square root of 61661977 is about 7852.5140560205. The cubic root of 61661977 is about 395.0685711217.

The spelling of 61661977 in words is "sixty-one million, six hundred sixty-one thousand, nine hundred seventy-seven".