21575401 has 2 divisors, whose sum is σ = 21575402. Its totient is φ = 21575400.

The previous prime is 21575387. The next prime is 21575413. The reversal of 21575401 is 10457512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11971600 + 9603801 = 3460^2 + 3099^2 .

It is a cyclic number.

It is not a de Polignac number, because 21575401 - 2¹¹ = 21573353 is a prime.

It is not a weakly prime, because it can be changed into another prime (21575201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10787700 + 10787701.

It is an arithmetic number, because the mean of its divisors is an integer number (10787701).

Almost surely, 2^21575401 is an apocalyptic number.

It is an amenable number.

21575401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21575401 is an equidigital number, since it uses as much as digits as its factorization.

21575401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 21575401 is about 4644.9328305154. The cubic root of 21575401 is about 278.3895690770.

The spelling of 21575401 in words is "twenty-one million, five hundred seventy-five thousand, four hundred one".