21871225740 has 192 divisors, whose sum is σ = 75450203136. Its totient is φ = 4609778688.

The previous prime is 21871225729. The next prime is 21871225777. The reversal of 21871225740 is 4752217812.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8150439 + ... + 8153121.

It is an arithmetic number, because the mean of its divisors is an integer number (392969808).

Almost surely, 2^21871225740 is an apocalyptic number.

21871225740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21871225740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37725101568).

21871225740 is an abundant number, since it is smaller than the sum of its proper divisors (53578977396).

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

21871225740 is a wasteful number, since it uses less digits than its factorization.

21871225740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4208 (or 4206 counting only the distinct ones).

The product of its (nonzero) digits is 62720, while the sum is 39.

The spelling of 21871225740 in words is "twenty-one billion, eight hundred seventy-one million, two hundred twenty-five thousand, seven hundred forty".