61990779 has 4 divisors (see below), whose sum is σ = 82654376. Its totient is φ = 41327184.

The previous prime is 61990763. The next prime is 61990801. The reversal of 61990779 is 97709916.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 61990779 - 2⁴ = 61990763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61990759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10331794 + ... + 10331799.

It is an arithmetic number, because the mean of its divisors is an integer number (20663594).

Almost surely, 2^61990779 is an apocalyptic number.

61990779 is a deficient number, since it is larger than the sum of its proper divisors (20663597).

61990779 is a wasteful number, since it uses less digits than its factorization.

61990779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20663596.

The product of its (nonzero) digits is 214326, while the sum is 48.

The square root of 61990779 is about 7873.4223181537. The cubic root of 61990779 is about 395.7695386412.

The spelling of 61990779 in words is "sixty-one million, nine hundred ninety thousand, seven hundred seventy-nine".