21040090890 has 192 divisors, whose sum is σ = 64334632320. Its totient is φ = 4363752960.

The previous prime is 21040090873. The next prime is 21040090931. The reversal of 21040090890 is 9809004012.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1118160 + ... + 1136820.

It is an arithmetic number, because the mean of its divisors is an integer number (335076210).

Almost surely, 2^21040090890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21040090890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32167316160).

21040090890 is an abundant number, since it is smaller than the sum of its proper divisors (43294541430).

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

21040090890 is a wasteful number, since it uses less digits than its factorization.

21040090890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18757 (or 18750 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The spelling of 21040090890 in words is "twenty-one billion, forty million, ninety thousand, eight hundred ninety".