21395693 has 8 divisors (see below), whose sum is σ = 23396736. Its totient is φ = 19404000.

The previous prime is 21395677. The next prime is 21395723. The reversal of 21395693 is 39659312.

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

It is not a de Polignac number, because 21395693 - 2⁴ = 21395677 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21395603) 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, 2993 + ... + 7193.

It is an arithmetic number, because the mean of its divisors is an integer number (2924592).

Almost surely, 2^21395693 is an apocalyptic number.

It is an amenable number.

21395693 is a deficient number, since it is larger than the sum of its proper divisors (2001043).

21395693 is a wasteful number, since it uses less digits than its factorization.

21395693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4675.

The product of its digits is 43740, while the sum is 38.

The square root of 21395693 is about 4625.5478594432. The cubic root of 21395693 is about 277.6144829693.

It can be divided in two parts, 21395 and 693, that multiplied together give a triangular number (14826735 = T₅₄₄₅).

The spelling of 21395693 in words is "twenty-one million, three hundred ninety-five thousand, six hundred ninety-three".