21766734 has 48 divisors (see below), whose sum is σ = 52565760. Its totient is φ = 6452880.

The previous prime is 21766721. The next prime is 21766739. The reversal of 21766734 is 43766712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21766739) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8137 + ... + 10475.

It is an arithmetic number, because the mean of its divisors is an integer number (1095120).

Almost surely, 2^21766734 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21766734, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26282880).

21766734 is an abundant number, since it is smaller than the sum of its proper divisors (30799026).

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

21766734 is a wasteful number, since it uses less digits than its factorization.

21766734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2405 (or 2402 counting only the distinct ones).

The product of its digits is 42336, while the sum is 36.

The square root of 21766734 is about 4665.4832547122. The cubic root of 21766734 is about 279.2100780291.

It can be divided in two parts, 21766 and 734, that added together give a square (22500 = 150²).

The spelling of 21766734 in words is "twenty-one million, seven hundred sixty-six thousand, seven hundred thirty-four".