21693407 has 2 divisors, whose sum is σ = 21693408. Its totient is φ = 21693406.

The previous prime is 21693403. The next prime is 21693437. The reversal of 21693407 is 70439612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21693407 - 2² = 21693403 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21693403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10846703 + 10846704.

It is an arithmetic number, because the mean of its divisors is an integer number (10846704).

Almost surely, 2^21693407 is an apocalyptic number.

21693407 is a deficient number, since it is larger than the sum of its proper divisors (1).

21693407 is an equidigital number, since it uses as much as digits as its factorization.

21693407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 21693407 is about 4657.6181681198. The cubic root of 21693407 is about 278.8961943017.

The spelling of 21693407 in words is "twenty-one million, six hundred ninety-three thousand, four hundred seven".