82643690 has 8 divisors (see below), whose sum is σ = 148758660. Its totient is φ = 33057472.

The previous prime is 82643689. The next prime is 82643699. The reversal of 82643690 is 9634628.

It can be written as a sum of positive squares in 2 ways, for example, as 78304801 + 4338889 = 8849^2 + 2083^2 .

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

It is a super-2 number, since 2×82643690² = 13659958993632200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (82643699) 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, 4132175 + ... + 4132194.

Almost surely, 2^82643690 is an apocalyptic number.

82643690 is a deficient number, since it is larger than the sum of its proper divisors (66114970).

82643690 is a wasteful number, since it uses less digits than its factorization.

82643690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8264376.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 82643690 is about 9090.8574953081. The cubic root of 82643690 is about 435.5819752599.

The spelling of 82643690 in words is "eighty-two million, six hundred forty-three thousand, six hundred ninety".