21537069 has 8 divisors (see below), whose sum is σ = 29120832. Its totient is φ = 14155680.

The previous prime is 21537049. The next prime is 21537073. The reversal of 21537069 is 96073512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21537069 - 2¹⁶ = 21471533 is a prime.

It is a super-2 number, since 2×21537069² = 927690682221522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537029) 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, 50344 + ... + 50769.

It is an arithmetic number, because the mean of its divisors is an integer number (3640104).

Almost surely, 2^21537069 is an apocalyptic number.

It is an amenable number.

21537069 is a deficient number, since it is larger than the sum of its proper divisors (7583763).

21537069 is a wasteful number, since it uses less digits than its factorization.

21537069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101187.

The product of its (nonzero) digits is 11340, while the sum is 33.

The square root of 21537069 is about 4640.8047793459. The cubic root of 21537069 is about 278.2246041262.

The spelling of 21537069 in words is "twenty-one million, five hundred thirty-seven thousand, sixty-nine".