21140431 has 8 divisors (see below), whose sum is σ = 23382464. Its totient is φ = 18986400.

The previous prime is 21140423. The next prime is 21140501. The reversal of 21140431 is 13404112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21140431 - 2³ = 21140423 is a prime.

It is a super-2 number, since 2×21140431² = 893835645731522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140731) 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 7 ways as a sum of consecutive naturals, for example, 21495 + ... + 22456.

It is an arithmetic number, because the mean of its divisors is an integer number (2922808).

Almost surely, 2^21140431 is an apocalyptic number.

21140431 is a deficient number, since it is larger than the sum of its proper divisors (2242033).

21140431 is a wasteful number, since it uses less digits than its factorization.

21140431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44001.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21140431 is about 4597.8724427718. The cubic root of 21140431 is about 276.5060335909.

Adding to 21140431 its reverse (13404112), we get a palindrome (34544543).

The spelling of 21140431 in words is "twenty-one million, one hundred forty thousand, four hundred thirty-one".