33971012821 has 4 divisors (see below), whose sum is σ = 33972311052. Its totient is φ = 33969714592.

The previous prime is 33971012783. The next prime is 33971012827. The reversal of 33971012821 is 12821017933.

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

It can be written as a sum of positive squares in 2 ways, for example, as 19178372196 + 14792640625 = 138486^2 + 121625^2 .

It is a cyclic number.

It is not a de Polignac number, because 33971012821 - 2²⁵ = 33937458389 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 (33971012827) 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, 609040 + ... + 662473.

It is an arithmetic number, because the mean of its divisors is an integer number (8493077763).

Almost surely, 2^33971012821 is an apocalyptic number.

It is an amenable number.

33971012821 is a deficient number, since it is larger than the sum of its proper divisors (1298231).

33971012821 is a wasteful number, since it uses less digits than its factorization.

33971012821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1298230.

The product of its (nonzero) digits is 18144, while the sum is 37.

The spelling of 33971012821 in words is "thirty-three billion, nine hundred seventy-one million, twelve thousand, eight hundred twenty-one".