997803878401 has 32 divisors (see below), whose sum is σ = 1119066584832. Its totient is φ = 881798400000.

The previous prime is 997803878339. The next prime is 997803878411. The reversal of 997803878401 is 104878308799.

It is a happy number.

It is a 3-Lehmer number, since φ(997803878401) divides (997803878401-1)³.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 997803878401 - 2¹³ = 997803870209 is a prime.

It is a super-2 number, since 2×997803878401² (a number of 25 digits) contains 22 as substring.

It is a deceptive number, since it divides R_997803878400.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997803878411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 153955081 + ... + 153961561.

It is an arithmetic number, because the mean of its divisors is an integer number (34970830776).

It is a Poulet number, since it divides 2^997803878400-1.

Almost surely, 2^997803878401 is an apocalyptic number.

It is an amenable number.

997803878401 is a deficient number, since it is larger than the sum of its proper divisors (121262706431).

997803878401 is a wasteful number, since it uses less digits than its factorization.

997803878401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7705.

The product of its (nonzero) digits is 24385536, while the sum is 64.

The spelling of 997803878401 in words is "nine hundred ninety-seven billion, eight hundred three million, eight hundred seventy-eight thousand, four hundred one".