1397816640 has 168 divisors, whose sum is σ = 5245108128. Its totient is φ = 338856960.

The previous prime is 1397816639. The next prime is 1397816659. The reversal of 1397816640 is 466187931.

It is a happy number.

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 23 ways as a sum of consecutive naturals, for example, 9619 + ... + 53741.

Almost surely, 2^1397816640 is an apocalyptic number.

1397816640 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 1397816640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2622554064).

1397816640 is an abundant number, since it is smaller than the sum of its proper divisors (3847291488).

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

1397816640 is a wasteful number, since it uses less digits than its factorization.

1397816640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44157 (or 44144 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1397816640 is about 37387.3861081515. The cubic root of 1397816640 is about 1118.1070917200.

The spelling of 1397816640 in words is "one billion, three hundred ninety-seven million, eight hundred sixteen thousand, six hundred forty".