21015342 has 16 divisors (see below), whose sum is σ = 46700880. Its totient is φ = 7005096.

The previous prime is 21015317. The next prime is 21015391. The reversal of 21015342 is 24351012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194533 + ... + 194640.

It is an arithmetic number, because the mean of its divisors is an integer number (2918805).

Almost surely, 2^21015342 is an apocalyptic number.

21015342 is an abundant number, since it is smaller than the sum of its proper divisors (25685538).

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

21015342 is a wasteful number, since it uses less digits than its factorization.

21015342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389184 (or 389178 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21015342 is about 4584.2493387686. The cubic root of 21015342 is about 275.9595876558.

Adding to 21015342 its reverse (24351012), we get a palindrome (45366354).

The spelling of 21015342 in words is "twenty-one million, fifteen thousand, three hundred forty-two".