83640905 has 16 divisors (see below), whose sum is σ = 104019984. Its totient is φ = 64512000.

The previous prime is 83640847. The next prime is 83640923. The reversal of 83640905 is 50904638.

It can be written as a sum of positive squares in 8 ways, for example, as 16581184 + 67059721 = 4072^2 + 8189^2 .

It is not a de Polignac number, because 83640905 - 2⁸ = 83640649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18905 + ... + 22905.

It is an arithmetic number, because the mean of its divisors is an integer number (6501249).

Almost surely, 2^83640905 is an apocalyptic number.

It is an amenable number.

83640905 is a deficient number, since it is larger than the sum of its proper divisors (20379079).

83640905 is a wasteful number, since it uses less digits than its factorization.

83640905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4156.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 83640905 is about 9145.5401699408. The cubic root of 83640905 is about 437.3269497915.

The spelling of 83640905 in words is "eighty-three million, six hundred forty thousand, nine hundred five".