21765342 has 32 divisors (see below), whose sum is σ = 45077760. Its totient is φ = 7001280.

The previous prime is 21765329. The next prime is 21765347. The reversal of 21765342 is 24356712.

It is a super-2 number, since 2×21765342² = 947460224753928, which contains 22 as substring.

21765342 is a Rhonda number in base 10.

Its product of digits (10080) is a multiple of the sum of its prime divisors (1008).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21765347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24909 + ... + 25767.

It is an arithmetic number, because the mean of its divisors is an integer number (1408680).

Almost surely, 2^21765342 is an apocalyptic number.

21765342 is an abundant number, since it is smaller than the sum of its proper divisors (23312418).

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

21765342 is a wasteful number, since it uses less digits than its factorization.

21765342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1008.

The product of its digits is 10080, while the sum is 30.

The square root of 21765342 is about 4665.3340716395. The cubic root of 21765342 is about 279.2041259998.

The spelling of 21765342 in words is "twenty-one million, seven hundred sixty-five thousand, three hundred forty-two".