21506754 has 8 divisors (see below), whose sum is σ = 43013520. Its totient is φ = 7168916.

The previous prime is 21506753. The next prime is 21506843. The reversal of 21506754 is 45760512.

It is a sphenic number, since it is the product of 3 distinct primes.

21506754 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21506753) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1792224 + ... + 1792235.

It is an arithmetic number, because the mean of its divisors is an integer number (5376690).

Almost surely, 2^21506754 is an apocalyptic number.

21506754 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21506754 is a wasteful number, since it uses less digits than its factorization.

21506754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3584464.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 21506754 is about 4637.5374931099. The cubic root of 21506754 is about 278.0940023359.

The spelling of 21506754 in words is "twenty-one million, five hundred six thousand, seven hundred fifty-four".