1997401680 has 280 divisors, whose sum is σ = 7208947080. Its totient is φ = 513838080.

The previous prime is 1997401669. The next prime is 1997401711. The reversal of 1997401680 is 861047991.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 601034256 + 1396367424 = 24516^2 + 37368^2 .

It is a super-2 number, since 2×1997401680² = 7979226942533644800, which 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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 1690690 + ... + 1691870.

Almost surely, 2^1997401680 is an apocalyptic number.

1997401680 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 1997401680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3604473540).

1997401680 is an abundant number, since it is smaller than the sum of its proper divisors (5211545400).

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

1997401680 is a wasteful number, since it uses less digits than its factorization.

1997401680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241 (or 1220 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 1997401680 is about 44692.3000079432. The cubic root of 1997401680 is about 1259.3752004343.

The spelling of 1997401680 in words is "one billion, nine hundred ninety-seven million, four hundred one thousand, six hundred eighty".