31426821 has 12 divisors (see below), whose sum is σ = 45444672. Its totient is φ = 20927976.

The previous prime is 31426799. The next prime is 31426823. The reversal of 31426821 is 12862413.

It is not a de Polignac number, because 31426821 - 2⁶ = 31426757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31426823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11620 + ... + 14066.

It is an arithmetic number, because the mean of its divisors is an integer number (3787056).

Almost surely, 2^31426821 is an apocalyptic number.

It is an amenable number.

31426821 is a deficient number, since it is larger than the sum of its proper divisors (14017851).

31426821 is a wasteful number, since it uses less digits than its factorization.

31426821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3880 (or 3877 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 31426821 is about 5605.9629859641. The cubic root of 31426821 is about 315.5732268247.

The spelling of 31426821 in words is "thirty-one million, four hundred twenty-six thousand, eight hundred twenty-one".