997978703400 has 1152 divisors, whose sum is σ = 4120686259200. Its totient is φ = 217432512000.

The previous prime is 997978703399. The next prime is 997978703413. The reversal of 997978703400 is 4307879799.

997978703400 is a `hidden beast` number, since 9 + 97 + 9 + 78 + 70 + 3 + 400 = 666.

It is a harmonic number, since the harmonic mean of its divisors is an integer.

It is a super-2 number, since 2×997978703400² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 3015041235 + ... + 3015041565.

It is an arithmetic number, because the mean of its divisors is an integer number (3576984600).

Almost surely, 2^997978703400 is an apocalyptic number.

997978703400 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 997978703400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2060343129600).

997978703400 is an abundant number, since it is smaller than the sum of its proper divisors (3122707555800).

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

997978703400 is a wasteful number, since it uses less digits than its factorization.

997978703400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508 (or 462 counting only the distinct ones).

The product of its (nonzero) digits is 24004512, while the sum is 63.

The spelling of 997978703400 in words is "nine hundred ninety-seven billion, nine hundred seventy-eight million, seven hundred three thousand, four hundred".