21634153 has 2 divisors, whose sum is σ = 21634154. Its totient is φ = 21634152.

The previous prime is 21634139. The next prime is 21634157. The reversal of 21634153 is 35143612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21270544 + 363609 = 4612^2 + 603^2 .

It is a cyclic number.

It is not a de Polignac number, because 21634153 - 2⁵ = 21634121 is a prime.

It is not a weakly prime, because it can be changed into another prime (21634157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10817076 + 10817077.

It is an arithmetic number, because the mean of its divisors is an integer number (10817077).

Almost surely, 2^21634153 is an apocalyptic number.

It is an amenable number.

21634153 is a deficient number, since it is larger than the sum of its proper divisors (1).

21634153 is an equidigital number, since it uses as much as digits as its factorization.

21634153 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 25.

The square root of 21634153 is about 4651.2528419771. The cubic root of 21634153 is about 278.6420343743.

Adding to 21634153 its reverse (35143612), we get a palindrome (56777765).

The spelling of 21634153 in words is "twenty-one million, six hundred thirty-four thousand, one hundred fifty-three".