21602401 has 2 divisors, whose sum is σ = 21602402. Its totient is φ = 21602400.

The previous prime is 21602369. The next prime is 21602417. The reversal of 21602401 is 10420612.

It is an a-pointer prime, because the next prime (21602417) can be obtained adding 21602401 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19571776 + 2030625 = 4424^2 + 1425^2 .

It is a cyclic number.

It is not a de Polignac number, because 21602401 - 2⁵ = 21602369 is a prime.

It is not a weakly prime, because it can be changed into another prime (21602431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10801200 + 10801201.

It is an arithmetic number, because the mean of its divisors is an integer number (10801201).

Almost surely, 2^21602401 is an apocalyptic number.

It is an amenable number.

21602401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21602401 is an equidigital number, since it uses as much as digits as its factorization.

21602401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21602401 is about 4647.8383147437. The cubic root of 21602401 is about 278.5056485741.

The spelling of 21602401 in words is "twenty-one million, six hundred two thousand, four hundred one".