83440721 has 8 divisors (see below), whose sum is σ = 102696384. Its totient is φ = 66018960.

The previous prime is 83440717. The next prime is 83440733. The reversal of 83440721 is 12704438.

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

It is not a de Polignac number, because 83440721 - 2² = 83440717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (83440751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 458375 + ... + 458556.

It is an arithmetic number, because the mean of its divisors is an integer number (12837048).

Almost surely, 2^83440721 is an apocalyptic number.

It is an amenable number.

83440721 is a deficient number, since it is larger than the sum of its proper divisors (19255663).

83440721 is a wasteful number, since it uses less digits than its factorization.

83440721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916951.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 83440721 is about 9134.5892627967. The cubic root of 83440721 is about 436.9777753675.

The spelling of 83440721 in words is "eighty-three million, four hundred forty thousand, seven hundred twenty-one".