21070401 has 16 divisors (see below), whose sum is σ = 30950400. Its totient is φ = 12643920.

The previous prime is 21070393. The next prime is 21070403. The reversal of 21070401 is 10407012.

It is not a de Polignac number, because 21070401 - 2³ = 21070393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21070403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 300 + ... + 6498.

It is an arithmetic number, because the mean of its divisors is an integer number (1934400).

Almost surely, 2^21070401 is an apocalyptic number.

It is an amenable number.

21070401 is a deficient number, since it is larger than the sum of its proper divisors (9879999).

21070401 is a wasteful number, since it uses less digits than its factorization.

21070401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6316.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 21070401 is about 4590.2506467512. The cubic root of 21070401 is about 276.2003769647.

Adding to 21070401 its reverse (10407012), we get a palindrome (31477413).

The spelling of 21070401 in words is "twenty-one million, seventy thousand, four hundred one".