71897784 has 64 divisors (see below), whose sum is σ = 206288640. Its totient is φ = 20455680.

The previous prime is 71897779. The next prime is 71897789. The reversal of 71897784 is 48779817.

It is an interprime number because it is at equal distance from previous prime (71897779) and next prime (71897789).

It is a super-2 number, since 2×71897784² = 10338582688221312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71897789) 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, 46447 + ... + 47969.

It is an arithmetic number, because the mean of its divisors is an integer number (3223260).

Almost surely, 2^71897784 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 71897784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103144320).

71897784 is an abundant number, since it is smaller than the sum of its proper divisors (134390856).

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

71897784 is a wasteful number, since it uses less digits than its factorization.

71897784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1820 (or 1816 counting only the distinct ones).

The product of its digits is 790272, while the sum is 51.

The square root of 71897784 is about 8479.2560994465. The cubic root of 71897784 is about 415.8198029965.

The spelling of 71897784 in words is "seventy-one million, eight hundred ninety-seven thousand, seven hundred eighty-four".