678891019 has 2 divisors, whose sum is σ = 678891020. Its totient is φ = 678891018.

The previous prime is 678891013. The next prime is 678891029. The reversal of 678891019 is 910198876.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 678891019 - 2⁵ = 678890987 is a prime.

It is a super-2 number, since 2×678891019² = 921786031357716722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (678891013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339445509 + 339445510.

It is an arithmetic number, because the mean of its divisors is an integer number (339445510).

Almost surely, 2^678891019 is an apocalyptic number.

678891019 is a deficient number, since it is larger than the sum of its proper divisors (1).

678891019 is an equidigital number, since it uses as much as digits as its factorization.

678891019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 49.

The square root of 678891019 is about 26055.5372042105. The cubic root of 678891019 is about 878.8876350539.

The spelling of 678891019 in words is "six hundred seventy-eight million, eight hundred ninety-one thousand, nineteen".