9781797840 has 80 divisors (see below), whose sum is σ = 30350128896. Its totient is φ = 2606195200.

The previous prime is 9781797829. The next prime is 9781797881. The reversal of 9781797840 is 487971879.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 266185 + ... + 300695.

Almost surely, 2^9781797840 is an apocalyptic number.

It is an amenable number.

9781797840 is an abundant number, since it is smaller than the sum of its proper divisors (20568331056).

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

9781797840 is a wasteful number, since it uses less digits than its factorization.

9781797840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35708 (or 35702 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 60.

The square root of 9781797840 is about 98902.9718461483. The cubic root of 9781797840 is about 2138.6492363798.

The spelling of 9781797840 in words is "nine billion, seven hundred eighty-one million, seven hundred ninety-seven thousand, eight hundred forty".