21765464 has 32 divisors (see below), whose sum is σ = 46997280. Its totient is φ = 9256704.

The previous prime is 21765463. The next prime is 21765479. The reversal of 21765464 is 46456712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21765463) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 6254 + ... + 9090.

It is an arithmetic number, because the mean of its divisors is an integer number (1468665).

Almost surely, 2^21765464 is an apocalyptic number.

It is an amenable number.

21765464 is an abundant number, since it is smaller than the sum of its proper divisors (25231816).

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

21765464 is a wasteful number, since it uses less digits than its factorization.

21765464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2987 (or 2983 counting only the distinct ones).

The product of its digits is 40320, while the sum is 35.

The square root of 21765464 is about 4665.3471467834. The cubic root of 21765464 is about 279.2046476677.

The spelling of 21765464 in words is "twenty-one million, seven hundred sixty-five thousand, four hundred sixty-four".