15622421 has 2 divisors, whose sum is σ = 15622422. Its totient is φ = 15622420.

The previous prime is 15622403. The next prime is 15622423. The reversal of 15622421 is 12422651.

It is a happy number.

15622421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8059921 + 7562500 = 2839^2 + 2750^2 .

It is an emirp because it is prime and its reverse (12422651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15622421 - 2¹⁸ = 15360277 is a prime.

Together with 15622423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15622423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7811210 + 7811211.

It is an arithmetic number, because the mean of its divisors is an integer number (7811211).

Almost surely, 2^15622421 is an apocalyptic number.

It is an amenable number.

15622421 is a deficient number, since it is larger than the sum of its proper divisors (1).

15622421 is an equidigital number, since it uses as much as digits as its factorization.

15622421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 23.

The square root of 15622421 is about 3952.5208411848. The cubic root of 15622421 is about 249.9862445765.

The spelling of 15622421 in words is "fifteen million, six hundred twenty-two thousand, four hundred twenty-one".