21311446 has 32 divisors (see below), whose sum is σ = 35981568. Its totient is φ = 9400320.

The previous prime is 21311443. The next prime is 21311447. The reversal of 21311446 is 64411312.

It is a super-2 number, since 2×21311446² = 908355461221832, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110326 + ... + 110518.

It is an arithmetic number, because the mean of its divisors is an integer number (1124424).

Almost surely, 2^21311446 is an apocalyptic number.

21311446 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21311446 is a deficient number, since it is larger than the sum of its proper divisors (14670122).

21311446 is a wasteful number, since it uses less digits than its factorization.

21311446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376.

The product of its digits is 576, while the sum is 22.

The square root of 21311446 is about 4616.4321721433. The cubic root of 21311446 is about 277.2496283511.

Adding to 21311446 its reverse (64411312), we get a palindrome (85722758).

The spelling of 21311446 in words is "twenty-one million, three hundred eleven thousand, four hundred forty-six".