21641464 has 24 divisors (see below), whose sum is σ = 43941960. Its totient is φ = 9987744.

The previous prime is 21641393. The next prime is 21641467. The reversal of 21641464 is 46414612.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21641467) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6652 + ... + 9355.

It is an arithmetic number, because the mean of its divisors is an integer number (1830915).

Almost surely, 2^21641464 is an apocalyptic number.

It is an amenable number.

21641464 is an abundant number, since it is smaller than the sum of its proper divisors (22300496).

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

21641464 is a wasteful number, since it uses less digits than its factorization.

21641464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16039 (or 16022 counting only the distinct ones).

The product of its digits is 4608, while the sum is 28.

The square root of 21641464 is about 4652.0386928743. The cubic root of 21641464 is about 278.6734187396.

The spelling of 21641464 in words is "twenty-one million, six hundred forty-one thousand, four hundred sixty-four".