21901867074 has 128 divisors (see below), whose sum is σ = 55168128000. Its totient is φ = 6398901504.

The previous prime is 21901867067. The next prime is 21901867079. The reversal of 21901867074 is 47076810912.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21901867079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1018437 + ... + 1039719.

It is an arithmetic number, because the mean of its divisors is an integer number (431001000).

Almost surely, 2^21901867074 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21901867074, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27584064000).

21901867074 is an abundant number, since it is smaller than the sum of its proper divisors (33266260926).

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

21901867074 is a wasteful number, since it uses less digits than its factorization.

21901867074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21389 (or 21383 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The spelling of 21901867074 in words is "twenty-one billion, nine hundred one million, eight hundred sixty-seven thousand, seventy-four".