21534963 has 8 divisors (see below), whose sum is σ = 29413776. Its totient is φ = 14006400.

The previous prime is 21534911. The next prime is 21534967. The reversal of 21534963 is 36943512.

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

It is not a de Polignac number, because 21534963 - 2⁶ = 21534899 is a prime.

It is a super-2 number, since 2×21534963² = 927509262822738, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21534967) 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, 87418 + ... + 87663.

It is an arithmetic number, because the mean of its divisors is an integer number (3676722).

Almost surely, 2^21534963 is an apocalyptic number.

21534963 is a deficient number, since it is larger than the sum of its proper divisors (7878813).

21534963 is a wasteful number, since it uses less digits than its factorization.

21534963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175125.

The product of its digits is 19440, while the sum is 33.

The square root of 21534963 is about 4640.5778734981. The cubic root of 21534963 is about 278.2155351095.

The spelling of 21534963 in words is "twenty-one million, five hundred thirty-four thousand, nine hundred sixty-three".