67216391 has 4 divisors (see below), whose sum is σ = 73326984. Its totient is φ = 61105800.

The previous prime is 67216381. The next prime is 67216397. The reversal of 67216391 is 19361276.

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

It is a cyclic number.

It is not a de Polignac number, because 67216391 - 2²² = 63022087 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 (67216397) 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, 3055280 + ... + 3055301.

It is an arithmetic number, because the mean of its divisors is an integer number (18331746).

Almost surely, 2^67216391 is an apocalyptic number.

67216391 is a deficient number, since it is larger than the sum of its proper divisors (6110593).

67216391 is a wasteful number, since it uses less digits than its factorization.

67216391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6110592.

The product of its digits is 13608, while the sum is 35.

The square root of 67216391 is about 8198.5603004430. The cubic root of 67216391 is about 406.5915951036.

The spelling of 67216391 in words is "sixty-seven million, two hundred sixteen thousand, three hundred ninety-one".