68640619 has 2 divisors, whose sum is σ = 68640620. Its totient is φ = 68640618.

The previous prime is 68640617. The next prime is 68640623. The reversal of 68640619 is 91604686.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 68640619 - 2¹ = 68640617 is a prime.

It is a super-2 number, since 2×68640619² = 9423069153406322, which contains 22 as substring.

Together with 68640617, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (68640613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34320309 + 34320310.

It is an arithmetic number, because the mean of its divisors is an integer number (34320310).

Almost surely, 2^68640619 is an apocalyptic number.

68640619 is a deficient number, since it is larger than the sum of its proper divisors (1).

68640619 is an equidigital number, since it uses as much as digits as its factorization.

68640619 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 68640619 is about 8284.9634278010. The cubic root of 68640619 is about 409.4432637867.

The spelling of 68640619 in words is "sixty-eight million, six hundred forty thousand, six hundred nineteen".