21742503 has 8 divisors (see below), whose sum is σ = 29481600. Its totient is φ = 14249208.

The previous prime is 21742493. The next prime is 21742571. The reversal of 21742503 is 30524712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21742503 - 2⁵ = 21742471 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21742583) 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, 61243 + ... + 61596.

It is an arithmetic number, because the mean of its divisors is an integer number (3685200).

Almost surely, 2^21742503 is an apocalyptic number.

21742503 is a deficient number, since it is larger than the sum of its proper divisors (7739097).

21742503 is a wasteful number, since it uses less digits than its factorization.

21742503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122901.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 21742503 is about 4662.8856945029. The cubic root of 21742503 is about 279.1064328452.

The spelling of 21742503 in words is "twenty-one million, seven hundred forty-two thousand, five hundred three".