78779961 has 24 divisors (see below), whose sum is σ = 122915520. Its totient is φ = 48334176.

The previous prime is 78779957. The next prime is 78779977. The reversal of 78779961 is 16997787.

It is not a de Polignac number, because 78779961 - 2² = 78779957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78779898 and 78779907.

It is not an unprimeable number, because it can be changed into a prime (78779941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48220 + ... + 49826.

It is an arithmetic number, because the mean of its divisors is an integer number (5121480).

Almost surely, 2^78779961 is an apocalyptic number.

It is an amenable number.

78779961 is a deficient number, since it is larger than the sum of its proper divisors (44135559).

78779961 is a wasteful number, since it uses less digits than its factorization.

78779961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2045 (or 2042 counting only the distinct ones).

The product of its digits is 1333584, while the sum is 54.

The square root of 78779961 is about 8875.8076252249. The cubic root of 78779961 is about 428.6852957915.

The spelling of 78779961 in words is "seventy-eight million, seven hundred seventy-nine thousand, nine hundred sixty-one".