82521619 has 4 divisors (see below), whose sum is σ = 82540744. Its totient is φ = 82502496.

The previous prime is 82521577. The next prime is 82521623. The reversal of 82521619 is 91612528.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 82521619 - 2¹⁵ = 82488851 is a prime.

It is a super-2 number, since 2×82521619² = 13619635204762322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82521319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 304 + ... + 12850.

It is an arithmetic number, because the mean of its divisors is an integer number (20635186).

Almost surely, 2^82521619 is an apocalyptic number.

82521619 is a deficient number, since it is larger than the sum of its proper divisors (19125).

82521619 is a wasteful number, since it uses less digits than its factorization.

82521619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19124.

The product of its digits is 8640, while the sum is 34.

The square root of 82521619 is about 9084.1410711195. The cubic root of 82521619 is about 435.3674070395.

Subtracting 82521619 from its reverse (91612528), we obtain a palindrome (9090909).

The spelling of 82521619 in words is "eighty-two million, five hundred twenty-one thousand, six hundred nineteen".