21034542 has 16 divisors (see below), whose sum is σ = 44543952. Its totient is φ = 6599040.

The previous prime is 21034513. The next prime is 21034543. The reversal of 21034542 is 24543012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21034543) 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, 103009 + ... + 103212.

It is an arithmetic number, because the mean of its divisors is an integer number (2783997).

Almost surely, 2^21034542 is an apocalyptic number.

21034542 is an abundant number, since it is smaller than the sum of its proper divisors (23509410).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21034542 is a wasteful number, since it uses less digits than its factorization.

21034542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206243.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21034542 is about 4586.3429876101. The cubic root of 21034542 is about 276.0436026471.

Adding to 21034542 its reverse (24543012), we get a palindrome (45577554).

The spelling of 21034542 in words is "twenty-one million, thirty-four thousand, five hundred forty-two".