21901271040 has 504 divisors, whose sum is σ = 83618963064. Its totient is φ = 5298585600.

The previous prime is 21901270973. The next prime is 21901271053. The reversal of 21901271040 is 4017210912.

It is a junction number, because it is equal to n+sod(n) for n = 21901270995 and 21901271013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 44605195 + ... + 44605685.

It is an arithmetic number, because the mean of its divisors is an integer number (165910641).

Almost surely, 2^21901271040 is an apocalyptic number.

21901271040 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 21901271040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41809481532).

21901271040 is an abundant number, since it is smaller than the sum of its proper divisors (61717692024).

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

21901271040 is a wasteful number, since it uses less digits than its factorization.

21901271040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

Adding to 21901271040 its reverse (4017210912), we get a palindrome (25918481952).

The spelling of 21901271040 in words is "twenty-one billion, nine hundred one million, two hundred seventy-one thousand, forty".