21092542 has 4 divisors (see below), whose sum is σ = 31638816. Its totient is φ = 10546270.

The previous prime is 21092507. The next prime is 21092543. The reversal of 21092542 is 24529012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21092543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5273134 + ... + 5273137.

It is an arithmetic number, because the mean of its divisors is an integer number (7909704).

Almost surely, 2^21092542 is an apocalyptic number.

21092542 is a deficient number, since it is larger than the sum of its proper divisors (10546274).

21092542 is a wasteful number, since it uses less digits than its factorization.

21092542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10546273.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21092542 is about 4592.6617554529. The cubic root of 21092542 is about 276.2970878558.

The spelling of 21092542 in words is "twenty-one million, ninety-two thousand, five hundred forty-two".