21525170501 has 2 divisors, whose sum is σ = 21525170502. Its totient is φ = 21525170500.

The previous prime is 21525170479. The next prime is 21525170531. The reversal of 21525170501 is 10507152512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19658844100 + 1866326401 = 140210^2 + 43201^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21525170501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21525170531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762585250 + 10762585251.

It is an arithmetic number, because the mean of its divisors is an integer number (10762585251).

Almost surely, 2^21525170501 is an apocalyptic number.

It is an amenable number.

21525170501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21525170501 is an equidigital number, since it uses as much as digits as its factorization.

21525170501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3500, while the sum is 29.

The spelling of 21525170501 in words is "twenty-one billion, five hundred twenty-five million, one hundred seventy thousand, five hundred one".