21911742 has 32 divisors (see below), whose sum is σ = 51559200. Its totient is φ = 6873984.

The previous prime is 21911741. The next prime is 21911767. The reversal of 21911742 is 24711912.

It is a super-3 number, since 3×21911742³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21911741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11017 + ... + 12852.

It is an arithmetic number, because the mean of its divisors is an integer number (1611225).

Almost surely, 2^21911742 is an apocalyptic number.

21911742 is an abundant number, since it is smaller than the sum of its proper divisors (29647458).

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

21911742 is a wasteful number, since it uses less digits than its factorization.

21911742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23897 (or 23891 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 21911742 is about 4680.9979705187. The cubic root of 21911742 is about 279.8287302935.

The spelling of 21911742 in words is "twenty-one million, nine hundred eleven thousand, seven hundred forty-two".