78399772 has 18 divisors (see below), whose sum is σ = 150807104. Its totient is φ = 35636040.

The previous prime is 78399689. The next prime is 78399779. The reversal of 78399772 is 27799387.

It is a happy number.

It is a super-2 number, since 2×78399772² = 12293048499303968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78399779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 80508 + ... + 81475.

Almost surely, 2^78399772 is an apocalyptic number.

It is an amenable number.

78399772 is a deficient number, since it is larger than the sum of its proper divisors (72407332).

78399772 is a wasteful number, since it uses less digits than its factorization.

78399772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162009 (or 161996 counting only the distinct ones).

The product of its digits is 1333584, while the sum is 52.

The square root of 78399772 is about 8854.3645734745. The cubic root of 78399772 is about 427.9945773325.

The spelling of 78399772 in words is "seventy-eight million, three hundred ninety-nine thousand, seven hundred seventy-two".