71963640 has 320 divisors, whose sum is σ = 292723200. Its totient is φ = 15489792.

The previous prime is 71963623. The next prime is 71963641. The reversal of 71963640 is 4636917.

71963640 is a `hidden beast` number, since 7 + 1 + 9 + 6 + 3 + 640 = 666.

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 = 71963595 and 71963604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71963641) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 430837 + ... + 431003.

It is an arithmetic number, because the mean of its divisors is an integer number (914760).

Almost surely, 2^71963640 is an apocalyptic number.

71963640 is a gapful number since it is divisible by the number (70) 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 71963640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146361600).

71963640 is an abundant number, since it is smaller than the sum of its proper divisors (220759560).

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

71963640 is a wasteful number, since it uses less digits than its factorization.

71963640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 71963640 is about 8483.1385701284. The cubic root of 71963640 is about 415.9467233301.

The spelling of 71963640 in words is "seventy-one million, nine hundred sixty-three thousand, six hundred forty".