21261433 has 2 divisors, whose sum is σ = 21261434. Its totient is φ = 21261432.

The previous prime is 21261413. The next prime is 21261463. The reversal of 21261433 is 33416212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16711744 + 4549689 = 4088^2 + 2133^2 .

It is a cyclic number.

It is not a de Polignac number, because 21261433 - 2¹³ = 21253241 is a prime.

It is not a weakly prime, because it can be changed into another prime (21261403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10630716 + 10630717.

It is an arithmetic number, because the mean of its divisors is an integer number (10630717).

Almost surely, 2^21261433 is an apocalyptic number.

It is an amenable number.

21261433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21261433 is an equidigital number, since it uses as much as digits as its factorization.

21261433 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 22.

The square root of 21261433 is about 4611.0121448550. The cubic root of 21261433 is about 277.0325783732.

Adding to 21261433 its reverse (33416212), we get a palindrome (54677645).

The spelling of 21261433 in words is "twenty-one million, two hundred sixty-one thousand, four hundred thirty-three".