7678513991 has 8 divisors (see below), whose sum is σ = 7827022224. Its totient is φ = 7531427200.

The previous prime is 7678513967. The next prime is 7678513993. The reversal of 7678513991 is 1993158767.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7678513991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7678513993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344450 + ... + 366063.

It is an arithmetic number, because the mean of its divisors is an integer number (978377778).

Almost surely, 2^7678513991 is an apocalyptic number.

7678513991 is a deficient number, since it is larger than the sum of its proper divisors (148508233).

7678513991 is a wasteful number, since it uses less digits than its factorization.

7678513991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 710721.

The product of its digits is 2857680, while the sum is 56.

The square root of 7678513991 is about 87627.1304505631. The cubic root of 7678513991 is about 1972.8424007931.

The spelling of 7678513991 in words is "seven billion, six hundred seventy-eight million, five hundred thirteen thousand, nine hundred ninety-one".