83618640 has 240 divisors, whose sum is σ = 328693248. Its totient is φ = 18653184.

The previous prime is 83618621. The next prime is 83618641. The reversal of 83618640 is 4681638.

It is a happy number.

83618640 is a `hidden beast` number, since 8 + 3 + 6 + 1 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 83618595 and 83618604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83618641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 236704 + ... + 237056.

Almost surely, 2^83618640 is an apocalyptic number.

83618640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 83618640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164346624).

83618640 is an abundant number, since it is smaller than the sum of its proper divisors (245074608).

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

83618640 is a wasteful number, since it uses less digits than its factorization.

83618640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426 (or 417 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 83618640 is about 9144.3228289469. The cubic root of 83618640 is about 437.2881412338.

The spelling of 83618640 in words is "eighty-three million, six hundred eighteen thousand, six hundred forty".