21121010190 has 192 divisors, whose sum is σ = 64433940480. Its totient is φ = 4699399680.

The previous prime is 21121010167. The next prime is 21121010221. The reversal of 21121010190 is 9101012112.

It is a happy number.

It is a super-2 number, since 2×21121010190² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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, 20327691 + ... + 20328729.

It is an arithmetic number, because the mean of its divisors is an integer number (335593440).

Almost surely, 2^21121010190 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121010190, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32216970240).

21121010190 is an abundant number, since it is smaller than the sum of its proper divisors (43312930290).

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

21121010190 is a wasteful number, since it uses less digits than its factorization.

21121010190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1887 (or 1884 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

The spelling of 21121010190 in words is "twenty-one billion, one hundred twenty-one million, ten thousand, one hundred ninety".