21210343438 has 8 divisors (see below), whose sum is σ = 31870656432. Its totient is φ = 10586791296.

The previous prime is 21210343417. The next prime is 21210343439. The reversal of 21210343438 is 83434301212.

It is a happy number.

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

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210343439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9188770 + ... + 9191077.

It is an arithmetic number, because the mean of its divisors is an integer number (3983832054).

Almost surely, 2^21210343438 is an apocalyptic number.

21210343438 is a deficient number, since it is larger than the sum of its proper divisors (10660312994).

21210343438 is a wasteful number, since it uses less digits than its factorization.

21210343438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18380426.

The product of its (nonzero) digits is 13824, while the sum is 31.

The spelling of 21210343438 in words is "twenty-one billion, two hundred ten million, three hundred forty-three thousand, four hundred thirty-eight".