21198429 has 50 divisors (see below), whose sum is σ = 37281310. Its totient is φ = 12002256.

The previous prime is 21198427. The next prime is 21198487. The reversal of 21198429 is 92489112.

It can be written as a sum of positive squares in only one way, i.e., 19448100 + 1750329 = 4410^2 + 1323^2 .

It is not a de Polignac number, because 21198429 - 2¹ = 21198427 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21198393 and 21198402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21198427) by changing a digit.

It is a polite number, since it can be written in 49 ways as a sum of consecutive naturals, for example, 194427 + ... + 194535.

Almost surely, 2^21198429 is an apocalyptic number.

It is an amenable number.

21198429 is a deficient number, since it is larger than the sum of its proper divisors (16082881).

21198429 is an frugal number, since it uses more digits than its factorization.

21198429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 119 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 21198429 is about 4604.1751704296. The cubic root of 21198429 is about 276.7586641040.

The spelling of 21198429 in words is "twenty-one million, one hundred ninety-eight thousand, four hundred twenty-nine".