82100640 has 48 divisors (see below), whose sum is σ = 258618528. Its totient is φ = 21893376.

The previous prime is 82100621. The next prime is 82100659. The reversal of 82100640 is 4600128.

It is an interprime number because it is at equal distance from previous prime (82100621) and next prime (82100659).

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85042 + ... + 86001.

It is an arithmetic number, because the mean of its divisors is an integer number (5387886).

Almost surely, 2^82100640 is an apocalyptic number.

82100640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

82100640 is an abundant number, since it is smaller than the sum of its proper divisors (176517888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

82100640 is a wasteful number, since it uses less digits than its factorization.

82100640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171061 (or 171053 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 82100640 is about 9060.9403485510. The cubic root of 82100640 is about 434.6258111240.

Adding to 82100640 its reverse (4600128), we get a palindrome (86700768).

The spelling of 82100640 in words is "eighty-two million, one hundred thousand, six hundred forty".