21132537 has 8 divisors (see below), whose sum is σ = 28597536.
Its totient is φ = 13877952.
The previous prime is 21132509. The next prime is 21132557. The reversal of 21132537 is 73523112.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 21132537 - 212 = 21128441 is a prime.
It is not an unprimeable number, because it can be changed into a prime (21132557) 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 in 7 ways as a sum of consecutive naturals, for example, 52368 + ... + 52769.
It is an arithmetic number, because the mean of its divisors is an integer number (3574692).
Almost surely, 221132537 is an apocalyptic number.
It is an amenable number.
21132537 is a deficient number, since it is larger than the sum of its proper divisors (7464999).
21132537 is a wasteful number, since it uses less digits than its factorization.
21132537 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 105207.
The product of its digits is 1260, while the sum is 24.
The square root of 21132537 is about 4597.0139221020.
The cubic root of 21132537 is about 276.4716128110.
Adding to 21132537 its reverse (73523112), we get a palindrome (94655649).
The spelling of 21132537 in words is "twenty-one million, one hundred thirty-two thousand, five hundred thirty-seven".