21752340 has 48 divisors (see below), whose sum is σ = 64115520. Its totient is φ = 5495040.

The previous prime is 21752329. The next prime is 21752369. The reversal of 21752340 is 4325712.

It is a self number, because there is not a number n which added to its sum of digits gives 21752340.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8401 + ... + 10680.

It is an arithmetic number, because the mean of its divisors is an integer number (1335740).

Almost surely, 2^21752340 is an apocalyptic number.

21752340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21752340 is an abundant number, since it is smaller than the sum of its proper divisors (42363180).

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

21752340 is a wasteful number, since it uses less digits than its factorization.

21752340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19112 (or 19110 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 21752340 is about 4663.9403941303. The cubic root of 21752340 is about 279.1485187084.

The spelling of 21752340 in words is "twenty-one million, seven hundred fifty-two thousand, three hundred forty".