997539840 has 480 divisors, whose sum is σ = 3963496320. Its totient is φ = 235929600.

The previous prime is 997539839. The next prime is 997539853. The reversal of 997539840 is 48935799.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24330220 + ... + 24330260.

It is an arithmetic number, because the mean of its divisors is an integer number (8257284).

Almost surely, 2^997539840 is an apocalyptic number.

997539840 is a gapful number since it is divisible by the number (90) 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 997539840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1981748160).

997539840 is an abundant number, since it is smaller than the sum of its proper divisors (2965956480).

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

997539840 is a wasteful number, since it uses less digits than its factorization.

997539840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 54.

The square root of 997539840 is about 31583.8541030065. The cubic root of 997539840 is about 999.1792732586.

The spelling of 997539840 in words is "nine hundred ninety-seven million, five hundred thirty-nine thousand, eight hundred forty".