82621 has 16 divisors (see below), whose sum is σ = 109440. Its totient is φ = 60480.

The previous prime is 82619. The next prime is 82633. The reversal of 82621 is 12628.

82621 = T₇₈ + T₇₉ + ... + T₉₈.

It is a happy number.

82621 is a nontrivial binomial coefficient, being equal to C(407, 2).

It is not a de Polignac number, because 82621 - 2¹ = 82619 is a prime.

It is a super-4 number, since 4×82621⁴ (a number of 21 digits) contains 4444 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82601) 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, 2215 + ... + 2251.

It is an arithmetic number, because the mean of its divisors is an integer number (6840).

2⁸²⁶²¹ is an apocalyptic number.

82621 is the 406-th triangular number and also the 154-th nonagonal number.

82621 is the 136-th centered nonagonal number.

It is an amenable number.

82621 is a deficient number, since it is larger than the sum of its proper divisors (26819).

82621 is a wasteful number, since it uses less digits than its factorization.

82621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84.

The product of its digits is 192, while the sum is 19.

The square root of 82621 is about 287.4386891147. The cubic root of 82621 is about 43.5542108293.

It can be divided in two parts, 82 and 621, that added together give a triangular number (703 = T₃₇).

The spelling of 82621 in words is "eighty-two thousand, six hundred twenty-one".