61819979 has 16 divisors (see below), whose sum is σ = 67858560. Its totient is φ = 55977600.

The previous prime is 61819957. The next prime is 61819997. The reversal of 61819979 is 97991816.

It is a cyclic number.

It is not a de Polignac number, because 61819979 - 2¹² = 61815883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61819579) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 258542 + ... + 258780.

It is an arithmetic number, because the mean of its divisors is an integer number (4241160).

Almost surely, 2^61819979 is an apocalyptic number.

61819979 is a deficient number, since it is larger than the sum of its proper divisors (6038581).

61819979 is a wasteful number, since it uses less digits than its factorization.

61819979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550.

The product of its digits is 244944, while the sum is 50.

The square root of 61819979 is about 7862.5682190999. The cubic root of 61819979 is about 395.4057231615.

The spelling of 61819979 in words is "sixty-one million, eight hundred nineteen thousand, nine hundred seventy-nine".