997398601920 has 224 divisors, whose sum is σ = 4021258099200. Its totient is φ = 227976809472.

The previous prime is 997398601877. The next prime is 997398602003. The reversal of 997398601920 is 29106893799.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is a super-2 number, since 2×997398601920² (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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8185210 + ... + 8306169.

Almost surely, 2^997398601920 is an apocalyptic number.

997398601920 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

997398601920 is an abundant number, since it is smaller than the sum of its proper divisors (3023859497280).

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

997398601920 is a wasteful number, since it uses less digits than its factorization.

997398601920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16491412 (or 16491396 counting only the distinct ones).

The product of its (nonzero) digits is 13226976, while the sum is 63.

The spelling of 997398601920 in words is "nine hundred ninety-seven billion, three hundred ninety-eight million, six hundred one thousand, nine hundred twenty".