34157721 has 16 divisors (see below), whose sum is σ = 49407680. Its totient is φ = 20865600.

The previous prime is 34157707. The next prime is 34157723. The reversal of 34157721 is 12775143.

It is not a de Polignac number, because 34157721 - 2⁵ = 34157689 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (34157723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2271 + ... + 8571.

It is an arithmetic number, because the mean of its divisors is an integer number (3087980).

Almost surely, 2^34157721 is an apocalyptic number.

It is an amenable number.

34157721 is a deficient number, since it is larger than the sum of its proper divisors (15249959).

34157721 is a wasteful number, since it uses less digits than its factorization.

34157721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6456.

The product of its digits is 5880, while the sum is 30.

The square root of 34157721 is about 5844.4607107927. The cubic root of 34157721 is about 324.4613436193.

The spelling of 34157721 in words is "thirty-four million, one hundred fifty-seven thousand, seven hundred twenty-one".