21417542 has 8 divisors (see below), whose sum is σ = 32151600. Its totient is φ = 10700344.

The previous prime is 21417523. The next prime is 21417547. The reversal of 21417542 is 24571412.

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

It is a super-2 number, since 2×21417542² = 917422210643528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21417547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 317 + ... + 6552.

It is an arithmetic number, because the mean of its divisors is an integer number (4018950).

Almost surely, 2^21417542 is an apocalyptic number.

21417542 is a deficient number, since it is larger than the sum of its proper divisors (10734058).

21417542 is a wasteful number, since it uses less digits than its factorization.

21417542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8430.

The product of its digits is 2240, while the sum is 26.

The square root of 21417542 is about 4627.9090310852. The cubic root of 21417542 is about 277.7089495722.

Adding to 21417542 its reverse (24571412), we get a palindrome (45988954).

The spelling of 21417542 in words is "twenty-one million, four hundred seventeen thousand, five hundred forty-two".