21129101 has 8 divisors (see below), whose sum is σ = 24206784. Its totient is φ = 18066240.

The previous prime is 21129077. The next prime is 21129107. The reversal of 21129101 is 10192112.

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

It is a cyclic number.

It is not a de Polignac number, because 21129101 - 2⁶ = 21129037 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21129101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21129107) 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, 455 + ... + 6516.

It is an arithmetic number, because the mean of its divisors is an integer number (3025848).

Almost surely, 2^21129101 is an apocalyptic number.

It is an amenable number.

21129101 is a deficient number, since it is larger than the sum of its proper divisors (3077683).

21129101 is an equidigital number, since it uses as much as digits as its factorization.

21129101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7411.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 21129101 is about 4596.6401860489. The cubic root of 21129101 is about 276.4566278938.

The spelling of 21129101 in words is "twenty-one million, one hundred twenty-nine thousand, one hundred one".