281564641 has 4 divisors (see below), whose sum is σ = 281662384. Its totient is φ = 281466900.

The previous prime is 281564627. The next prime is 281564651. The reversal of 281564641 is 146465182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 281564641 - 2⁵ = 281564609 is a prime.

It is a super-2 number, since 2×281564641² = 158557294122917762, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 281564641.

It is not an unprimeable number, because it can be changed into a prime (281564651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44415 + ... + 50356.

It is an arithmetic number, because the mean of its divisors is an integer number (70415596).

Almost surely, 2^281564641 is an apocalyptic number.

It is an amenable number.

281564641 is a deficient number, since it is larger than the sum of its proper divisors (97743).

281564641 is an equidigital number, since it uses as much as digits as its factorization.

281564641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97742.

The product of its digits is 46080, while the sum is 37.

The square root of 281564641 is about 16779.8879912829. The cubic root of 281564641 is about 655.4295812595.

The spelling of 281564641 in words is "two hundred eighty-one million, five hundred sixty-four thousand, six hundred forty-one".