21435590394 has 48 divisors (see below), whose sum is σ = 49305784320. Its totient is φ = 6707111040.

The previous prime is 21435590387. The next prime is 21435590399. The reversal of 21435590394 is 49309553412.

21435590394 is a `hidden beast` number, since 2 + 1 + 4 + 3 + 559 + 0 + 3 + 94 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21435590399) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23559 + ... + 208389.

It is an arithmetic number, because the mean of its divisors is an integer number (1027203840).

Almost surely, 2^21435590394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21435590394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24652892160).

21435590394 is an abundant number, since it is smaller than the sum of its proper divisors (27870193926).

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

21435590394 is a wasteful number, since it uses less digits than its factorization.

21435590394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185235 (or 185232 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 45.

The spelling of 21435590394 in words is "twenty-one billion, four hundred thirty-five million, five hundred ninety thousand, three hundred ninety-four".