21270701 has 4 divisors (see below), whose sum is σ = 21481404. Its totient is φ = 21060000.

The previous prime is 21270679. The next prime is 21270707. The reversal of 21270701 is 10707212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8561476 + 12709225 = 2926^2 + 3565^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21270701 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21270707) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105200 + ... + 105401.

It is an arithmetic number, because the mean of its divisors is an integer number (5370351).

Almost surely, 2^21270701 is an apocalyptic number.

It is an amenable number.

21270701 is a deficient number, since it is larger than the sum of its proper divisors (210703).

21270701 is a wasteful number, since it uses less digits than its factorization.

21270701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210702.

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 21270701 is about 4612.0170207839. The cubic root of 21270701 is about 277.0728259732.

Adding to 21270701 its reverse (10707212), we get a palindrome (31977913).

The spelling of 21270701 in words is "twenty-one million, two hundred seventy thousand, seven hundred one".