21529023 has 8 divisors (see below), whose sum is σ = 28820736. Its totient is φ = 14295000.

The previous prime is 21529019. The next prime is 21529051. The reversal of 21529023 is 32092512.

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

It is not a de Polignac number, because 21529023 - 2² = 21529019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21528984 and 21529002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21529003) 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, 13543 + ... + 15048.

It is an arithmetic number, because the mean of its divisors is an integer number (3602592).

Almost surely, 2^21529023 is an apocalyptic number.

21529023 is a deficient number, since it is larger than the sum of its proper divisors (7291713).

21529023 is a wasteful number, since it uses less digits than its factorization.

21529023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28845.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21529023 is about 4639.9378228593. The cubic root of 21529023 is about 278.1899526454.

It can be divided in two parts, 2152 and 9023, that added together give a triangular number (11175 = T₁₄₉).

The spelling of 21529023 in words is "twenty-one million, five hundred twenty-nine thousand, twenty-three".