21532673 has 4 divisors (see below), whose sum is σ = 21603120. Its totient is φ = 21462228.

The previous prime is 21532663. The next prime is 21532697. The reversal of 21532673 is 37623512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21532673 - 2⁸ = 21532417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21532603) 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, 34763 + ... + 35376.

It is an arithmetic number, because the mean of its divisors is an integer number (5400780).

Almost surely, 2^21532673 is an apocalyptic number.

It is an amenable number.

21532673 is a deficient number, since it is larger than the sum of its proper divisors (70447).

21532673 is an equidigital number, since it uses as much as digits as its factorization.

21532673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70446.

The product of its digits is 7560, while the sum is 29.

The square root of 21532673 is about 4640.3311304259. The cubic root of 21532673 is about 278.2056730670.

It can be divided in two parts, 21532 and 673, that multiplied together give a triangular number (14491036 = T₅₃₈₃).

The spelling of 21532673 in words is "twenty-one million, five hundred thirty-two thousand, six hundred seventy-three".