1997390461440 has 960 divisors, whose sum is σ = 7490355586560. Its totient is φ = 449059553280.

The previous prime is 1997390461433. The next prime is 1997390461441. The reversal of 1997390461440 is 441640937991.

It is a tau number, because it is divible by the number of its divisors (960).

It is a super-2 number, since 2×1997390461440² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (1997390461441) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4508781859 + ... + 4508782301.

It is an arithmetic number, because the mean of its divisors is an integer number (7802453736).

Almost surely, 2^{1997390461440} is an apocalyptic number.

1997390461440 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 1997390461440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3745177793280).

1997390461440 is an abundant number, since it is smaller than the sum of its proper divisors (5492965125120).

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

1997390461440 is a wasteful number, since it uses less digits than its factorization.

1997390461440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605 (or 536 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 57.

The spelling of 1997390461440 in words is "one trillion, nine hundred ninety-seven billion, three hundred ninety million, four hundred sixty-one thousand, four hundred forty".