21352129 has 4 divisors (see below), whose sum is σ = 21520384. Its totient is φ = 21183876.

The previous prime is 21352127. The next prime is 21352139. The reversal of 21352129 is 92125312.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21352129 - 2¹ = 21352127 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21352127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83937 + ... + 84190.

It is an arithmetic number, because the mean of its divisors is an integer number (5380096).

Almost surely, 2^21352129 is an apocalyptic number.

It is an amenable number.

21352129 is a deficient number, since it is larger than the sum of its proper divisors (168255).

21352129 is a wasteful number, since it uses less digits than its factorization.

21352129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168254.

The product of its digits is 1080, while the sum is 25.

The square root of 21352129 is about 4620.8363961517. The cubic root of 21352129 is about 277.4259370024.

The spelling of 21352129 in words is "twenty-one million, three hundred fifty-two thousand, one hundred twenty-nine".