21431034 has 16 divisors (see below), whose sum is σ = 47624640. Its totient is φ = 7143660.

The previous prime is 21431023. The next prime is 21431057. The reversal of 21431034 is 43013412.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21430998 and 21431016.

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, 198382 + ... + 198489.

It is an arithmetic number, because the mean of its divisors is an integer number (2976540).

Almost surely, 2^21431034 is an apocalyptic number.

21431034 is an abundant number, since it is smaller than the sum of its proper divisors (26193606).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21431034 is a wasteful number, since it uses less digits than its factorization.

21431034 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396882 (or 396876 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 21431034 is about 4629.3664793360. The cubic root of 21431034 is about 277.7672516663.

Adding to 21431034 its reverse (43013412), we get a palindrome (64444446).

The spelling of 21431034 in words is "twenty-one million, four hundred thirty-one thousand, thirty-four".