71633640 has 128 divisors (see below), whose sum is σ = 236597760. Its totient is φ = 17240064.

The previous prime is 71633623. The next prime is 71633647. The reversal of 71633640 is 4633617.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 71633598 and 71633607.

It is not an unprimeable number, because it can be changed into a prime (71633647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72832 + ... + 73808.

It is an arithmetic number, because the mean of its divisors is an integer number (1848420).

Almost surely, 2^71633640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71633640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118298880).

71633640 is an abundant number, since it is smaller than the sum of its proper divisors (164964120).

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

71633640 is a wasteful number, since it uses less digits than its factorization.

71633640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1051 (or 1047 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 30.

The square root of 71633640 is about 8463.6658724219. The cubic root of 71633640 is about 415.3099537648.

The spelling of 71633640 in words is "seventy-one million, six hundred thirty-three thousand, six hundred forty".