82214721 has 6 divisors (see below), whose sum is σ = 118754610. Its totient is φ = 54809808.

The previous prime is 82214711. The next prime is 82214723. The reversal of 82214721 is 12741228.

It can be written as a sum of positive squares in only one way, i.e., 52403121 + 29811600 = 7239^2 + 5460^2 .

It is not a de Polignac number, because 82214721 - 2⁵ = 82214689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (82214723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4567476 + ... + 4567493.

It is an arithmetic number, because the mean of its divisors is an integer number (19792435).

Almost surely, 2^82214721 is an apocalyptic number.

It is an amenable number.

82214721 is a deficient number, since it is larger than the sum of its proper divisors (36539889).

82214721 is a wasteful number, since it uses less digits than its factorization.

82214721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9134975 (or 9134972 counting only the distinct ones).

The product of its digits is 1792, while the sum is 27.

The square root of 82214721 is about 9067.2333707697. The cubic root of 82214721 is about 434.8270259560.

Adding to 82214721 its reverse (12741228), we get a palindrome (94955949).

The spelling of 82214721 in words is "eighty-two million, two hundred fourteen thousand, seven hundred twenty-one".