21010553 has 2 divisors, whose sum is σ = 21010554. Its totient is φ = 21010552.

The previous prime is 21010547. The next prime is 21010567. The reversal of 21010553 is 35501012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11505664 + 9504889 = 3392^2 + 3083^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010553 - 2⁶ = 21010489 is a prime.

It is not a weakly prime, because it can be changed into another prime (21010543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505276 + 10505277.

It is an arithmetic number, because the mean of its divisors is an integer number (10505277).

Almost surely, 2^21010553 is an apocalyptic number.

It is an amenable number.

21010553 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010553 is an equidigital number, since it uses as much as digits as its factorization.

21010553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 21010553 is about 4583.7269770352. The cubic root of 21010553 is about 275.9386240686.

Adding to 21010553 its reverse (35501012), we get a palindrome (56511565).

The spelling of 21010553 in words is "twenty-one million, ten thousand, five hundred fifty-three".