1397571840 has 576 divisors, whose sum is σ = 5827852800. Its totient is φ = 310542336.

The previous prime is 1397571727. The next prime is 1397571863. The reversal of 1397571840 is 481757931.

1397571840 is a `hidden beast` number, since 1 + 39 + 7 + 571 + 8 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

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

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, 12821706 + ... + 12821814.

It is an arithmetic number, because the mean of its divisors is an integer number (10117800).

Almost surely, 2^1397571840 is an apocalyptic number.

1397571840 is a gapful number since it is divisible by the number (10) 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 1397571840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2913926400).

1397571840 is an abundant number, since it is smaller than the sum of its proper divisors (4430280960).

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

1397571840 is a wasteful number, since it uses less digits than its factorization.

1397571840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 45.

The square root of 1397571840 is about 37384.1121333649. The cubic root of 1397571840 is about 1118.0418164451.

The spelling of 1397571840 in words is "one billion, three hundred ninety-seven million, five hundred seventy-one thousand, eight hundred forty".