21740494 has 16 divisors (see below), whose sum is σ = 33382368. Its totient is φ = 10615072.

The previous prime is 21740491. The next prime is 21740533. The reversal of 21740494 is 49404712.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21740491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33279 + ... + 33925.

It is an arithmetic number, because the mean of its divisors is an integer number (2086398).

Almost surely, 2^21740494 is an apocalyptic number.

21740494 is a deficient number, since it is larger than the sum of its proper divisors (11641874).

21740494 is a wasteful number, since it uses less digits than its factorization.

21740494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1019.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21740494 is about 4662.6702649876. The cubic root of 21740494 is about 279.0978361334.

The spelling of 21740494 in words is "twenty-one million, seven hundred forty thousand, four hundred ninety-four".