82215551 has 16 divisors (see below), whose sum is σ = 93774240. Its totient is φ = 71393280.

The previous prime is 82215487. The next prime is 82215563. The reversal of 82215551 is 15551228.

It is a cyclic number.

It is not a de Polignac number, because 82215551 - 2⁶ = 82215487 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82215151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29615 + ... + 32271.

It is an arithmetic number, because the mean of its divisors is an integer number (5860890).

Almost surely, 2^82215551 is an apocalyptic number.

82215551 is a deficient number, since it is larger than the sum of its proper divisors (11558689).

82215551 is a wasteful number, since it uses less digits than its factorization.

82215551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2794.

The product of its digits is 4000, while the sum is 29.

The square root of 82215551 is about 9067.2791398523. The cubic root of 82215551 is about 434.8284892187.

Adding to 82215551 its reverse (15551228), we get a palindrome (97766779).

The spelling of 82215551 in words is "eighty-two million, two hundred fifteen thousand, five hundred fifty-one".