21494542 has 4 divisors (see below), whose sum is σ = 32241816. Its totient is φ = 10747270.

The previous prime is 21494531. The next prime is 21494569. The reversal of 21494542 is 24549412.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5373634 + ... + 5373637.

It is an arithmetic number, because the mean of its divisors is an integer number (8060454).

Almost surely, 2^21494542 is an apocalyptic number.

21494542 is a deficient number, since it is larger than the sum of its proper divisors (10747274).

21494542 is a wasteful number, since it uses less digits than its factorization.

21494542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10747273.

The product of its digits is 11520, while the sum is 31.

The square root of 21494542 is about 4636.2206591145. The cubic root of 21494542 is about 278.0413564407.

The spelling of 21494542 in words is "twenty-one million, four hundred ninety-four thousand, five hundred forty-two".