21881450812 has 24 divisors (see below), whose sum is σ = 42568383872. Its totient is φ = 9773352000.

The previous prime is 21881450797. The next prime is 21881450819. The reversal of 21881450812 is 21805418812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21881450819) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6785439 + ... + 6788662.

Almost surely, 2^21881450812 is an apocalyptic number.

It is an amenable number.

21881450812 is a deficient number, since it is larger than the sum of its proper divisors (20686933060).

21881450812 is a wasteful number, since it uses less digits than its factorization.

21881450812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13574149 (or 13574147 counting only the distinct ones).

The product of its (nonzero) digits is 40960, while the sum is 40.

The spelling of 21881450812 in words is "twenty-one billion, eight hundred eighty-one million, four hundred fifty thousand, eight hundred twelve".