678721901 has 32 divisors (see below), whose sum is σ = 813189888. Its totient is φ = 558397440.

The previous prime is 678721891. The next prime is 678721903. The reversal of 678721901 is 109127876.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-678721901 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 (678721903) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2316311 + ... + 2316603.

It is an arithmetic number, because the mean of its divisors is an integer number (25412184).

Almost surely, 2^678721901 is an apocalyptic number.

It is an amenable number.

678721901 is a deficient number, since it is larger than the sum of its proper divisors (134467987).

678721901 is a wasteful number, since it uses less digits than its factorization.

678721901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581.

The product of its (nonzero) digits is 42336, while the sum is 41.

The square root of 678721901 is about 26052.2916650340. The cubic root of 678721901 is about 878.8146493273.

The spelling of 678721901 in words is "six hundred seventy-eight million, seven hundred twenty-one thousand, nine hundred one".