21449868940 has 24 divisors (see below), whose sum is σ = 45490716432. Its totient is φ = 8494996800.

The previous prime is 21449868929. The next prime is 21449868941. The reversal of 21449868940 is 4986894412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21449868941) 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, 5307354 + ... + 5311393.

It is an arithmetic number, because the mean of its divisors is an integer number (1895446518).

Almost surely, 2^21449868940 is an apocalyptic number.

21449868940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21449868940 is an abundant number, since it is smaller than the sum of its proper divisors (24040847492).

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

21449868940 is a wasteful number, since it uses less digits than its factorization.

21449868940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10618857 (or 10618855 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 55.

The spelling of 21449868940 in words is "twenty-one billion, four hundred forty-nine million, eight hundred sixty-eight thousand, nine hundred forty".