67720871 has 4 divisors (see below), whose sum is σ = 67748712. Its totient is φ = 67693032.

The previous prime is 67720847. The next prime is 67720879. The reversal of 67720871 is 17802776.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67720871 is a prime.

It is a super-2 number, since 2×67720871² = 9172232737997282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67720879) 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, 9881 + ... + 15266.

It is an arithmetic number, because the mean of its divisors is an integer number (16937178).

Almost surely, 2^67720871 is an apocalyptic number.

67720871 is a deficient number, since it is larger than the sum of its proper divisors (27841).

67720871 is a wasteful number, since it uses less digits than its factorization.

67720871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27840.

The product of its (nonzero) digits is 32928, while the sum is 38.

The square root of 67720871 is about 8229.2691656064. The cubic root of 67720871 is about 407.6062598173.

The spelling of 67720871 in words is "sixty-seven million, seven hundred twenty thousand, eight hundred seventy-one".