21524412157 has 2 divisors, whose sum is σ = 21524412158. Its totient is φ = 21524412156.

The previous prime is 21524412121. The next prime is 21524412179. The reversal of 21524412157 is 75121442512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19134082276 + 2390329881 = 138326^2 + 48891^2 .

It is a cyclic number.

It is not a de Polignac number, because 21524412157 - 2²⁷ = 21390194429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21524412457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762206078 + 10762206079.

It is an arithmetic number, because the mean of its divisors is an integer number (10762206079).

Almost surely, 2^21524412157 is an apocalyptic number.

It is an amenable number.

21524412157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21524412157 is an equidigital number, since it uses as much as digits as its factorization.

21524412157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22400, while the sum is 34.

Adding to 21524412157 its reverse (75121442512), we get a palindrome (96645854669).

The spelling of 21524412157 in words is "twenty-one billion, five hundred twenty-four million, four hundred twelve thousand, one hundred fifty-seven".