74721 has 4 divisors (see below), whose sum is σ = 99632. Its totient is φ = 49812.

The previous prime is 74719. The next prime is 74729. The reversal of 74721 is 12747.

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 not a de Polignac number, because 74721 - 2¹ = 74719 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

74721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (74729) 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, 12451 + ... + 12456.

It is an arithmetic number, because the mean of its divisors is an integer number (24908).

2⁷⁴⁷²¹ is an apocalyptic number.

It is an amenable number.

74721 is a deficient number, since it is larger than the sum of its proper divisors (24911).

74721 is a wasteful number, since it uses less digits than its factorization.

74721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24910.

The product of its digits is 392, while the sum is 21.

The square root of 74721 is about 273.3514221657. The cubic root of 74721 is about 42.1192754624.

The spelling of 74721 in words is "seventy-four thousand, seven hundred twenty-one", and thus it is an iban number.