21429446544 has 135 divisors (see below), whose sum is σ = 65979886609. Its totient is φ = 6487916160.

The previous prime is 21429446527. The next prime is 21429446551. The reversal of 21429446544 is 44564492412.

The square root of 21429446544 is 146388.

It is a perfect power (a square), and thus also a powerful number.

21429446544 is a `hidden beast` number, since 2 + 14 + 2 + 94 + 4 + 6 + 544 = 666.

It can be written as a sum of positive squares in only one way, i.e., 346406544 + 21083040000 = 18612^2 + 145200^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21429446544.

It is an unprimeable number.

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 26 ways as a sum of consecutive naturals, for example, 19322662 + ... + 19323770.

Almost surely, 2^21429446544 is an apocalyptic number.

21429446544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

21429446544 is the 146388-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21429446544

21429446544 is an abundant number, since it is smaller than the sum of its proper divisors (44550440065).

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

21429446544 is a wasteful number, since it uses less digits than its factorization.

21429446544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2254 (or 1125 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 45.

The spelling of 21429446544 in words is "twenty-one billion, four hundred twenty-nine million, four hundred forty-six thousand, five hundred forty-four".