83021721 has 8 divisors (see below), whose sum is σ = 110743584. Its totient is φ = 55323840.

The previous prime is 83021713. The next prime is 83021749. The reversal of 83021721 is 12712038.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 83021721 - 2³ = 83021713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 83021691 and 83021700.

It is not an unprimeable number, because it can be changed into a prime (83022721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4930 + ... + 13796.

It is an arithmetic number, because the mean of its divisors is an integer number (13842948).

Almost surely, 2^83021721 is an apocalyptic number.

It is an amenable number.

83021721 is a deficient number, since it is larger than the sum of its proper divisors (27721863).

83021721 is a wasteful number, since it uses less digits than its factorization.

83021721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11991.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 83021721 is about 9111.6255959077. The cubic root of 83021721 is about 436.2451154479.

Adding to 83021721 its reverse (12712038), we get a palindrome (95733759).

The spelling of 83021721 in words is "eighty-three million, twenty-one thousand, seven hundred twenty-one".