21742551846 has 224 divisors, whose sum is σ = 55060443360. Its totient is φ = 6395977728.

The previous prime is 21742551841. The next prime is 21742551851. The reversal of 21742551846 is 64815524712.

21742551846 is a `hidden beast` number, since 2 + 1 + 74 + 25 + 518 + 46 = 666.

It is an interprime number because it is at equal distance from previous prime (21742551841) and next prime (21742551851).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21742551841) 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 111 ways as a sum of consecutive naturals, for example, 64517790 + ... + 64518126.

Almost surely, 2^21742551846 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21742551846, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27530221680).

21742551846 is an abundant number, since it is smaller than the sum of its proper divisors (33317891514).

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

21742551846 is a wasteful number, since it uses less digits than its factorization.

21742551846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530 (or 515 counting only the distinct ones).

The product of its digits is 537600, while the sum is 45.

The spelling of 21742551846 in words is "twenty-one billion, seven hundred forty-two million, five hundred fifty-one thousand, eight hundred forty-six".