21140434 has 16 divisors (see below), whose sum is σ = 37084608. Its totient is φ = 8849232.

The previous prime is 21140423. The next prime is 21140501. The reversal of 21140434 is 43404112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16957 + ... + 18160.

It is an arithmetic number, because the mean of its divisors is an integer number (2317788).

Almost surely, 2^21140434 is an apocalyptic number.

21140434 is a deficient number, since it is larger than the sum of its proper divisors (15944174).

21140434 is a wasteful number, since it uses less digits than its factorization.

21140434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35169.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21140434 is about 4597.8727690096. The cubic root of 21140434 is about 276.5060466704.

Adding to 21140434 its reverse (43404112), we get a palindrome (64544546).

It can be divided in two parts, 211404 and 34, that multiplied together give a triangular number (7187736 = T₃₇₉₁).

The spelling of 21140434 in words is "twenty-one million, one hundred forty thousand, four hundred thirty-four".