61779641 has 24 divisors (see below), whose sum is σ = 79727040. Its totient is φ = 47325600.

The previous prime is 61779637. The next prime is 61779643. The reversal of 61779641 is 14697716.

It is not a de Polignac number, because 61779641 - 2² = 61779637 is a prime.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61779643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31940 + ... + 33818.

It is an arithmetic number, because the mean of its divisors is an integer number (3321960).

Almost surely, 2^61779641 is an apocalyptic number.

61779641 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

61779641 is a deficient number, since it is larger than the sum of its proper divisors (17947399).

61779641 is a wasteful number, since it uses less digits than its factorization.

61779641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1965 (or 1958 counting only the distinct ones).

The product of its digits is 63504, while the sum is 41.

The square root of 61779641 is about 7860.0026081421. The cubic root of 61779641 is about 395.3197027158.

Subtracting from 61779641 its sum of digits (41), we obtain a square (61779600 = 7860²).

The spelling of 61779641 in words is "sixty-one million, seven hundred seventy-nine thousand, six hundred forty-one".