71643398400 has 648 divisors, whose sum is σ = 303621025344. Its totient is φ = 16373145600.

The previous prime is 71643398399. The next prime is 71643398423. The reversal of 71643398400 is 489334617.

71643398400 is a `hidden beast` number, since 71 + 64 + 33 + 98 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (648).

It is a super-2 number, since 2×71643398400² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 10883110 + ... + 10889690.

Almost surely, 2^71643398400 is an apocalyptic number.

71643398400 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 71643398400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151810512672).

71643398400 is an abundant number, since it is smaller than the sum of its proper divisors (231977626944).

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

71643398400 is an equidigital number, since it uses as much as digits as its factorization.

71643398400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6629 (or 6598 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 71643398400 in words is "seventy-one billion, six hundred forty-three million, three hundred ninety-eight thousand, four hundred".