21421401 has 8 divisors (see below), whose sum is σ = 29546880. Its totient is φ = 13788432.

The previous prime is 21421399. The next prime is 21421427. The reversal of 21421401 is 10412412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21421401 - 2¹ = 21421399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21421451) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123025 + ... + 123198.

It is an arithmetic number, because the mean of its divisors is an integer number (3693360).

Almost surely, 2^21421401 is an apocalyptic number.

It is an amenable number.

21421401 is a deficient number, since it is larger than the sum of its proper divisors (8125479).

21421401 is a wasteful number, since it uses less digits than its factorization.

21421401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246255.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 21421401 is about 4628.3259392571. The cubic root of 21421401 is about 277.7256277151.

Adding to 21421401 its reverse (10412412), we get a palindrome (31833813).

The spelling of 21421401 in words is "twenty-one million, four hundred twenty-one thousand, four hundred one".