21910138206 has 32 divisors (see below), whose sum is σ = 47866864896. Its totient is φ = 6630696000.

The previous prime is 21910138193. The next prime is 21910138223. The reversal of 21910138206 is 60283101912.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167890 + ... + 268341.

It is an arithmetic number, because the mean of its divisors is an integer number (1495839528).

Almost surely, 2^21910138206 is an apocalyptic number.

21910138206 is an abundant number, since it is smaller than the sum of its proper divisors (25956726690).

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

21910138206 is a wasteful number, since it uses less digits than its factorization.

21910138206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437008.

The product of its (nonzero) digits is 5184, while the sum is 33.

The spelling of 21910138206 in words is "twenty-one billion, nine hundred ten million, one hundred thirty-eight thousand, two hundred six".