281561431 has 2 divisors, whose sum is σ = 281561432. Its totient is φ = 281561430.

The previous prime is 281561417. The next prime is 281561459. The reversal of 281561431 is 134165182.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 281561431 - 2⁷ = 281561303 is a prime.

It is a super-2 number, since 2×281561431² = 158553678853535522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 281561393 and 281561402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (281561411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140780715 + 140780716.

It is an arithmetic number, because the mean of its divisors is an integer number (140780716).

Almost surely, 2^281561431 is an apocalyptic number.

281561431 is a deficient number, since it is larger than the sum of its proper divisors (1).

281561431 is an equidigital number, since it uses as much as digits as its factorization.

281561431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 31.

The square root of 281561431 is about 16779.7923407890. The cubic root of 281561431 is about 655.4270904910.

It can be divided in two parts, 2815 and 61431, that added together give a palindrome (64246).

The spelling of 281561431 in words is "two hundred eighty-one million, five hundred sixty-one thousand, four hundred thirty-one".