21768270 has 64 divisors (see below), whose sum is σ = 54743040. Its totient is φ = 5532800.

The previous prime is 21768269. The next prime is 21768289. The reversal of 21768270 is 7286712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 113875 + ... + 114065.

It is an arithmetic number, because the mean of its divisors is an integer number (855360).

Almost surely, 2^21768270 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21768270, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27371520).

21768270 is an abundant number, since it is smaller than the sum of its proper divisors (32974770).

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

21768270 is a wasteful number, since it uses less digits than its factorization.

21768270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361.

The product of its (nonzero) digits is 9408, while the sum is 33.

The square root of 21768270 is about 4665.6478649808. The cubic root of 21768270 is about 279.2166454911.

The spelling of 21768270 in words is "twenty-one million, seven hundred sixty-eight thousand, two hundred seventy".