71857981440 has 768 divisors, whose sum is σ = 295500441600. Its totient is φ = 16224288768.

The previous prime is 71857981397. The next prime is 71857981457. The reversal of 71857981440 is 4418975817.

71857981440 is a `hidden beast` number, since 7 + 18 + 579 + 8 + 14 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (768).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 207083347 + ... + 207083693.

It is an arithmetic number, because the mean of its divisors is an integer number (384766200).

Almost surely, 2^71857981440 is an apocalyptic number.

71857981440 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 71857981440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147750220800).

71857981440 is an abundant number, since it is smaller than the sum of its proper divisors (223642460160).

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

71857981440 is a wasteful number, since it uses less digits than its factorization.

71857981440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 54.

The spelling of 71857981440 in words is "seventy-one billion, eight hundred fifty-seven million, nine hundred eighty-one thousand, four hundred forty".