998560781 has 16 divisors (see below), whose sum is σ = 1043582400. Its totient is φ = 954633600.

The previous prime is 998560753. The next prime is 998560811. The reversal of 998560781 is 187065899.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998560781 is a prime.

It is a super-2 number, since 2×998560781² = 1994247266702659922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998560481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1230866 + ... + 1231676.

It is an arithmetic number, because the mean of its divisors is an integer number (65223900).

Almost surely, 2^998560781 is an apocalyptic number.

It is an amenable number.

998560781 is a deficient number, since it is larger than the sum of its proper divisors (45021619).

998560781 is a wasteful number, since it uses less digits than its factorization.

998560781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1420.

The product of its (nonzero) digits is 1088640, while the sum is 53.

The square root of 998560781 is about 31600.0123575925. The cubic root of 998560781 is about 999.5200299990.

The spelling of 998560781 in words is "nine hundred ninety-eight million, five hundred sixty thousand, seven hundred eighty-one".