1998641280 has 64 divisors (see below), whose sum is σ = 6370675200. Its totient is φ = 532970496.

The previous prime is 1998641273. The next prime is 1998641297. The reversal of 1998641280 is 821468991.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×1998641280² = 7989133932240076800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518560 + ... + 522399.

It is an arithmetic number, because the mean of its divisors is an integer number (99541800).

Almost surely, 2^1998641280 is an apocalyptic number.

1998641280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1998641280 is an abundant number, since it is smaller than the sum of its proper divisors (4372033920).

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

1998641280 is a wasteful number, since it uses less digits than its factorization.

1998641280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040981 (or 1040969 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 48.

The square root of 1998641280 is about 44706.1660176759. The cubic root of 1998641280 is about 1259.6356719388.

The spelling of 1998641280 in words is "one billion, nine hundred ninety-eight million, six hundred forty-one thousand, two hundred eighty".