67679721 has 24 divisors (see below), whose sum is σ = 100694880. Its totient is φ = 43779456.

The previous prime is 67679699. The next prime is 67679741. The reversal of 67679721 is 12797676.

It is a de Polignac number, because none of the positive numbers 2^k-67679721 is a prime.

It is not an unprimeable number, because it can be changed into a prime (67679741) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68785 + ... + 69761.

It is an arithmetic number, because the mean of its divisors is an integer number (4195620).

Almost surely, 2^67679721 is an apocalyptic number.

It is an amenable number.

67679721 is a deficient number, since it is larger than the sum of its proper divisors (33015159).

67679721 is a wasteful number, since it uses less digits than its factorization.

67679721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205 (or 1202 counting only the distinct ones).

The product of its digits is 222264, while the sum is 45.

The square root of 67679721 is about 8226.7685636585. The cubic root of 67679721 is about 407.5236836198.

The spelling of 67679721 in words is "sixty-seven million, six hundred seventy-nine thousand, seven hundred twenty-one".