21262401 has 6 divisors (see below), whose sum is σ = 30712370. Its totient is φ = 14174928.

The previous prime is 21262399. The next prime is 21262411. The reversal of 21262401 is 10426212.

21262401 is a `hidden beast` number, since 2 + 1 + 262 + 401 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20930625 + 331776 = 4575^2 + 576^2 .

It is not a de Polignac number, because 21262401 - 2¹ = 21262399 is a prime.

It is a super-4 number, since 4×21262401⁴ (a number of 30 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21262411) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1181236 + ... + 1181253.

Almost surely, 2^21262401 is an apocalyptic number.

It is an amenable number.

21262401 is a deficient number, since it is larger than the sum of its proper divisors (9449969).

21262401 is a wasteful number, since it uses less digits than its factorization.

21262401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2362495 (or 2362492 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21262401 is about 4611.1171097685. The cubic root of 21262401 is about 277.0367825969.

Adding to 21262401 its reverse (10426212), we get a palindrome (31688613).

The spelling of 21262401 in words is "twenty-one million, two hundred sixty-two thousand, four hundred one".