83921405 has 16 divisors (see below), whose sum is σ = 102529584. Its totient is φ = 65932800.

The previous prime is 83921399. The next prime is 83921407. The reversal of 83921405 is 50412938.

It can be written as a sum of positive squares in 8 ways, for example, as 52441 + 83868964 = 229^2 + 9158^2 .

It is a de Polignac number, because none of the positive numbers 2^k-83921405 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83921407) 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, 68579 + ... + 69791.

It is an arithmetic number, because the mean of its divisors is an integer number (6408099).

Almost surely, 2^83921405 is an apocalyptic number.

It is an amenable number.

83921405 is a deficient number, since it is larger than the sum of its proper divisors (18608179).

83921405 is a wasteful number, since it uses less digits than its factorization.

83921405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1456.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 83921405 is about 9160.8626777176. The cubic root of 83921405 is about 437.8152807681.

The spelling of 83921405 in words is "eighty-three million, nine hundred twenty-one thousand, four hundred five".