67401721 has 4 divisors (see below), whose sum is σ = 70949200. Its totient is φ = 63854244.

The previous prime is 67401709. The next prime is 67401731. The reversal of 67401721 is 12710476.

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 67401721 - 2⁵ = 67401689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 67401721.

It is not an unprimeable number, because it can be changed into a prime (67401731) 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, 1773711 + ... + 1773748.

It is an arithmetic number, because the mean of its divisors is an integer number (17737300).

Almost surely, 2^67401721 is an apocalyptic number.

It is an amenable number.

67401721 is a deficient number, since it is larger than the sum of its proper divisors (3547479).

67401721 is a wasteful number, since it uses less digits than its factorization.

67401721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3547478.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 67401721 is about 8209.8551144341. The cubic root of 67401721 is about 406.9649389152.

The spelling of 67401721 in words is "sixty-seven million, four hundred one thousand, seven hundred twenty-one".