1981124280 has 48 divisors (see below), whose sum is σ = 6438655080. Its totient is φ = 528299712.

The previous prime is 1981124269. The next prime is 1981124287. The reversal of 1981124280 is 824211891.

It is a happy number.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981124287) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2751202 + ... + 2751921.

Almost surely, 2^1981124280 is an apocalyptic number.

1981124280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981124280 is an abundant number, since it is smaller than the sum of its proper divisors (4457530800).

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

1981124280 is a wasteful number, since it uses less digits than its factorization.

1981124280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5503140 (or 5503133 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 1981124280 is about 44509.8222867717. The cubic root of 1981124280 is about 1255.9448618066.

The spelling of 1981124280 in words is "one billion, nine hundred eighty-one million, one hundred twenty-four thousand, two hundred eighty".