21394612746 has 48 divisors (see below), whose sum is σ = 50435463624. Its totient is φ = 6515085312.

The previous prime is 21394612717. The next prime is 21394612747. The reversal of 21394612746 is 64721649312.

21394612746 is a `hidden beast` number, since 21 + 3 + 9 + 4 + 612 + 7 + 4 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 6195421521 + 15199191225 = 78711^2 + 123285^2 .

It is not an unprimeable number, because it can be changed into a prime (21394612747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 448591 + ... + 493986.

Almost surely, 2^21394612746 is an apocalyptic number.

21394612746 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21394612746 is an abundant number, since it is smaller than the sum of its proper divisors (29040850878).

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

21394612746 is a wasteful number, since it uses less digits than its factorization.

21394612746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942695 (or 942692 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The spelling of 21394612746 in words is "twenty-one billion, three hundred ninety-four million, six hundred twelve thousand, seven hundred forty-six".