21401207 has 16 divisors (see below), whose sum is σ = 22790880. Its totient is φ = 20072448.

The previous prime is 21401203. The next prime is 21401251. The reversal of 21401207 is 70210412.

It is a cyclic number.

It is not a de Polignac number, because 21401207 - 2² = 21401203 is a prime.

It is a super-2 number, since 2×21401207² = 916023322113698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401203) 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, 220583 + ... + 220679.

It is an arithmetic number, because the mean of its divisors is an integer number (1424430).

Almost surely, 2^21401207 is an apocalyptic number.

21401207 is a deficient number, since it is larger than the sum of its proper divisors (1389673).

21401207 is an equidigital number, since it uses as much as digits as its factorization.

21401207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 21401207 is about 4626.1438585500. The cubic root of 21401207 is about 277.6383294319.

Adding to 21401207 its reverse (70210412), we get a palindrome (91611619).

The spelling of 21401207 in words is "twenty-one million, four hundred one thousand, two hundred seven".