21422401 has 16 divisors (see below), whose sum is σ = 28764288. Its totient is φ = 15408000.

The previous prime is 21422399. The next prime is 21422411. The reversal of 21422401 is 10422412.

It is a cyclic number.

It is not a de Polignac number, because 21422401 - 2¹ = 21422399 is a prime.

It is a deceptive number, since it divides R_21422400.

It is not an unprimeable number, because it can be changed into a prime (21422411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9700 + ... + 11701.

It is an arithmetic number, because the mean of its divisors is an integer number (1797768).

Almost surely, 2^21422401 is an apocalyptic number.

It is an amenable number.

21422401 is a deficient number, since it is larger than the sum of its proper divisors (7341887).

21422401 is a wasteful number, since it uses less digits than its factorization.

21422401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21432.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21422401 is about 4628.4339684174. The cubic root of 21422401 is about 277.7299492704.

Adding to 21422401 its reverse (10422412), we get a palindrome (31844813).

The spelling of 21422401 in words is "twenty-one million, four hundred twenty-two thousand, four hundred one".