21545524001 has 2 divisors, whose sum is σ = 21545524002. Its totient is φ = 21545524000.

The previous prime is 21545523949. The next prime is 21545524003. The reversal of 21545524001 is 10042554512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19902437776 + 1643086225 = 141076^2 + 40535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21545524001 is a prime.

Together with 21545524003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21545524003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772762000 + 10772762001.

It is an arithmetic number, because the mean of its divisors is an integer number (10772762001).

Almost surely, 2^21545524001 is an apocalyptic number.

It is an amenable number.

21545524001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21545524001 is an equidigital number, since it uses as much as digits as its factorization.

21545524001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8000, while the sum is 29.

The spelling of 21545524001 in words is "twenty-one billion, five hundred forty-five million, five hundred twenty-four thousand, one".