21241057 has 2 divisors, whose sum is σ = 21241058. Its totient is φ = 21241056.

The previous prime is 21241049. The next prime is 21241081. The reversal of 21241057 is 75014212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20151121 + 1089936 = 4489^2 + 1044^2 .

It is a cyclic number.

It is not a de Polignac number, because 21241057 - 2³ = 21241049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21241037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10620528 + 10620529.

It is an arithmetic number, because the mean of its divisors is an integer number (10620529).

Almost surely, 2^21241057 is an apocalyptic number.

It is an amenable number.

21241057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21241057 is an equidigital number, since it uses as much as digits as its factorization.

21241057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21241057 is about 4608.8021220269. The cubic root of 21241057 is about 276.9440515709.

Adding to 21241057 its reverse (75014212), we get a palindrome (96255269).

The spelling of 21241057 in words is "twenty-one million, two hundred forty-one thousand, fifty-seven".