281991420 has 72 divisors (see below), whose sum is σ = 875290416. Its totient is φ = 73446912.

The previous prime is 281991419. The next prime is 281991433. The reversal of 281991420 is 24199182.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct 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 an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10477 + ... + 25956.

Almost surely, 2^281991420 is an apocalyptic number.

281991420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

281991420 is an abundant number, since it is smaller than the sum of its proper divisors (593298996).

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

281991420 is a wasteful number, since it uses less digits than its factorization.

281991420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36491 (or 36486 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 281991420 is about 16792.6001560211. The cubic root of 281991420 is about 655.7605678607.

The spelling of 281991420 in words is "two hundred eighty-one million, nine hundred ninety-one thousand, four hundred twenty".