21315038 has 4 divisors (see below), whose sum is σ = 31972560. Its totient is φ = 10657518.

The previous prime is 21315037. The next prime is 21315053. The reversal of 21315038 is 83051312.

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 (21315031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5328758 + ... + 5328761.

It is an arithmetic number, because the mean of its divisors is an integer number (7993140).

Almost surely, 2^21315038 is an apocalyptic number.

21315038 is a deficient number, since it is larger than the sum of its proper divisors (10657522).

21315038 is a wasteful number, since it uses less digits than its factorization.

21315038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10657521.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21315038 is about 4616.8212007831. The cubic root of 21315038 is about 277.2652040925.

It can be divided in two parts, 213 and 15038, that added together give a palindrome (15251).

The spelling of 21315038 in words is "twenty-one million, three hundred fifteen thousand, thirty-eight".