68720649 has 4 divisors (see below), whose sum is σ = 91627536. Its totient is φ = 45813764.

The previous prime is 68720629. The next prime is 68720657. The reversal of 68720649 is 94602786.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 68720649 - 2¹⁹ = 68196361 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 68720649.

It is not an unprimeable number, because it can be changed into a prime (68720629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11453439 + ... + 11453444.

It is an arithmetic number, because the mean of its divisors is an integer number (22906884).

Almost surely, 2^68720649 is an apocalyptic number.

It is an amenable number.

68720649 is a deficient number, since it is larger than the sum of its proper divisors (22906887).

68720649 is a wasteful number, since it uses less digits than its factorization.

68720649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22906886.

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 68720649 is about 8289.7918550468. The cubic root of 68720649 is about 409.6023290661.

The spelling of 68720649 in words is "sixty-eight million, seven hundred twenty thousand, six hundred forty-nine".