1397126640 has 640 divisors, whose sum is σ = 5831626752. Its totient is φ = 268369920.

The previous prime is 1397126629. The next prime is 1397126641. The reversal of 1397126640 is 466217931.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1397126641) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 19677805 + ... + 19677875.

Almost surely, 2^1397126640 is an apocalyptic number.

1397126640 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 1397126640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2915813376).

1397126640 is an abundant number, since it is smaller than the sum of its proper divisors (4434500112).

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

1397126640 is a wasteful number, since it uses less digits than its factorization.

1397126640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 39.

The square root of 1397126640 is about 37378.1572579495. The cubic root of 1397126640 is about 1117.9230854993.

The spelling of 1397126640 in words is "one billion, three hundred ninety-seven million, one hundred twenty-six thousand, six hundred forty".