21401355 has 16 divisors (see below), whose sum is σ = 35168544. Its totient is φ = 11105280.

The previous prime is 21401327. The next prime is 21401363. The reversal of 21401355 is 55310412.

It is not a de Polignac number, because 21401355 - 2⁵ = 21401323 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18726 + ... + 19835.

It is an arithmetic number, because the mean of its divisors is an integer number (2198034).

Almost surely, 2^21401355 is an apocalyptic number.

21401355 is a deficient number, since it is larger than the sum of its proper divisors (13767189).

21401355 is a wasteful number, since it uses less digits than its factorization.

21401355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38606.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21401355 is about 4626.1598545662. The cubic root of 21401355 is about 277.6389694328.

Adding to 21401355 its reverse (55310412), we get a palindrome (76711767).

The spelling of 21401355 in words is "twenty-one million, four hundred one thousand, three hundred fifty-five".