67978881 has 6 divisors (see below), whose sum is σ = 98191730. Its totient is φ = 45319248.

The previous prime is 67978849. The next prime is 67978907. The reversal of 67978881 is 18887976.

It can be written as a sum of positive squares in only one way, i.e., 59907600 + 8071281 = 7740^2 + 2841^2 .

It is not a de Polignac number, because 67978881 - 2⁵ = 67978849 is a prime.

It is a super-2 number, since 2×67978881² = 9242256524024322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67978481) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3776596 + ... + 3776613.

Almost surely, 2^67978881 is an apocalyptic number.

It is an amenable number.

67978881 is a deficient number, since it is larger than the sum of its proper divisors (30212849).

67978881 is a wasteful number, since it uses less digits than its factorization.

67978881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7553215 (or 7553212 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The square root of 67978881 is about 8244.9306243291. The cubic root of 67978881 is about 408.1232506822.

The spelling of 67978881 in words is "sixty-seven million, nine hundred seventy-eight thousand, eight hundred eighty-one".