21911801240 has 32 divisors (see below), whose sum is σ = 56344632480. Its totient is φ = 7512617472.

The previous prime is 21911801213. The next prime is 21911801251. The reversal of 21911801240 is 4210811912.

It is a congruent number.

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, 39127937 + ... + 39128496.

It is an arithmetic number, because the mean of its divisors is an integer number (1760769765).

Almost surely, 2^21911801240 is an apocalyptic number.

21911801240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21911801240 is an abundant number, since it is smaller than the sum of its proper divisors (34432831240).

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

21911801240 is a wasteful number, since it uses less digits than its factorization.

21911801240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78256451 (or 78256447 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 29.

The spelling of 21911801240 in words is "twenty-one billion, nine hundred eleven million, eight hundred one thousand, two hundred forty".