997501680 has 240 divisors, whose sum is σ = 3910892544. Its totient is φ = 223096320.

The previous prime is 997501657. The next prime is 997501709. The reversal of 997501680 is 86105799.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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 47 ways as a sum of consecutive naturals, for example, 234775 + ... + 238985.

Almost surely, 2^997501680 is an apocalyptic number.

997501680 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

997501680 is the 15792-nd decagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 997501680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1955446272).

997501680 is an abundant number, since it is smaller than the sum of its proper divisors (2913390864).

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

997501680 is a wasteful number, since it uses less digits than its factorization.

997501680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4284 (or 4275 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 997501680 is about 31583.2499910950. The cubic root of 997501680 is about 999.1665321911.

The spelling of 997501680 in words is "nine hundred ninety-seven million, five hundred one thousand, six hundred eighty".