21461760 has 252 divisors, whose sum is σ = 80427312. Its totient is φ = 5474304.

The previous prime is 21461753. The next prime is 21461777. The reversal of 21461760 is 6716412.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 933109 + ... + 933131.

It is an arithmetic number, because the mean of its divisors is an integer number (319156).

Almost surely, 2^21461760 is an apocalyptic number.

21461760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21461760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40213656).

21461760 is an abundant number, since it is smaller than the sum of its proper divisors (58965552).

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

21461760 is an frugal number, since it uses more digits than its factorization.

21461760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62 (or 33 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21461760 is about 4632.6838873379. The cubic root of 21461760 is about 277.8999346570.

The spelling of 21461760 in words is "twenty-one million, four hundred sixty-one thousand, seven hundred sixty".