21438943810 has 16 divisors (see below), whose sum is σ = 38591914752. Its totient is φ = 8575174000.

The previous prime is 21438943807. The next prime is 21438943847. The reversal of 21438943810 is 1834983412.

It is a super-2 number, since 2×21438943810² (a number of 21 digits) contains 22 as substring.

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

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, 269085 + ... + 339535.

It is an arithmetic number, because the mean of its divisors is an integer number (2411994672).

Almost surely, 2^21438943810 is an apocalyptic number.

21438943810 is a deficient number, since it is larger than the sum of its proper divisors (17152970942).

21438943810 is a wasteful number, since it uses less digits than its factorization.

21438943810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100889.

The product of its (nonzero) digits is 165888, while the sum is 43.

The spelling of 21438943810 in words is "twenty-one billion, four hundred thirty-eight million, nine hundred forty-three thousand, eight hundred ten".