21431030 has 16 divisors (see below), whose sum is σ = 38938320. Its totient is φ = 8491872.

The previous prime is 21431023. The next prime is 21431057. The reversal of 21431030 is 3013412.

It is a junction number, because it is equal to n+sod(n) for n = 21430996 and 21431014.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8945 + ... + 11084.

It is an arithmetic number, because the mean of its divisors is an integer number (2433645).

Almost surely, 2^21431030 is an apocalyptic number.

21431030 is a deficient number, since it is larger than the sum of its proper divisors (17507290).

21431030 is a wasteful number, since it uses less digits than its factorization.

21431030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20143.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21431030 is about 4629.3660473114. The cubic root of 21431030 is about 277.7672343850.

Adding to 21431030 its reverse (3013412), we get a palindrome (24444442).

The spelling of 21431030 in words is "twenty-one million, four hundred thirty-one thousand, thirty".