21007693 has 16 divisors (see below), whose sum is σ = 24938496. Its totient is φ = 17322480.

The previous prime is 21007691. The next prime is 21007709. The reversal of 21007693 is 39670012.

It is not a de Polignac number, because 21007693 - 2¹ = 21007691 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21007691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20880 + ... + 21862.

It is an arithmetic number, because the mean of its divisors is an integer number (1558656).

Almost surely, 2^21007693 is an apocalyptic number.

It is an amenable number.

21007693 is a deficient number, since it is larger than the sum of its proper divisors (3930803).

21007693 is an equidigital number, since it uses as much as digits as its factorization.

21007693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1104.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 21007693 is about 4583.4149932119. The cubic root of 21007693 is about 275.9261030547.

The spelling of 21007693 in words is "twenty-one million, seven thousand, six hundred ninety-three".