1998174780 has 144 divisors (see below), whose sum is σ = 6998846400. Its totient is φ = 451989504.

The previous prime is 1998174769. The next prime is 1998174799. The reversal of 1998174780 is 874718991.

1998174780 = 308² + 309² + ... + 1819².

1998174780 is a `hidden beast` number, since 1 + 99 + 81 + 7 + 478 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 114046 + ... + 130394.

It is an arithmetic number, because the mean of its divisors is an integer number (48603100).

Almost surely, 2^1998174780 is an apocalyptic number.

1998174780 is a gapful number since it is divisible by the number (10) 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 1998174780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3499423200).

1998174780 is an abundant number, since it is smaller than the sum of its proper divisors (5000671620).

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

1998174780 is a wasteful number, since it uses less digits than its factorization.

1998174780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16468 (or 16463 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 54.

The square root of 1998174780 is about 44700.9483120884. The cubic root of 1998174780 is about 1259.5376610599.

The spelling of 1998174780 in words is "one billion, nine hundred ninety-eight million, one hundred seventy-four thousand, seven hundred eighty".