21263029 has 4 divisors (see below), whose sum is σ = 21331276. Its totient is φ = 21194784.

The previous prime is 21262999. The next prime is 21263041. The reversal of 21263029 is 92036212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8468100 + 12794929 = 2910^2 + 3577^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21263029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21262994 and 21263012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21263059) 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, 33654 + ... + 34279.

It is an arithmetic number, because the mean of its divisors is an integer number (5332819).

Almost surely, 2^21263029 is an apocalyptic number.

It is an amenable number.

21263029 is a deficient number, since it is larger than the sum of its proper divisors (68247).

21263029 is an equidigital number, since it uses as much as digits as its factorization.

21263029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68246.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21263029 is about 4611.1852055627. The cubic root of 21263029 is about 277.0395100623.

The spelling of 21263029 in words is "twenty-one million, two hundred sixty-three thousand, twenty-nine".