34720821 has 6 divisors (see below), whose sum is σ = 50152310. Its totient is φ = 23147208.

The previous prime is 34720813. The next prime is 34720843. The reversal of 34720821 is 12802743.

It can be written as a sum of positive squares in only one way, i.e., 27185796 + 7535025 = 5214^2 + 2745^2 .

It is not a de Polignac number, because 34720821 - 2³ = 34720813 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 (34730821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1928926 + ... + 1928943.

Almost surely, 2^34720821 is an apocalyptic number.

It is an amenable number.

34720821 is a deficient number, since it is larger than the sum of its proper divisors (15431489).

34720821 is a wasteful number, since it uses less digits than its factorization.

34720821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3857875 (or 3857872 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 34720821 is about 5892.4376110401. The cubic root of 34720821 is about 326.2345815587.

The spelling of 34720821 in words is "thirty-four million, seven hundred twenty thousand, eight hundred twenty-one".