21352561501 has 2 divisors, whose sum is σ = 21352561502. Its totient is φ = 21352561500.

The previous prime is 21352561463. The next prime is 21352561523. The reversal of 21352561501 is 10516525312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13496398276 + 7856163225 = 116174^2 + 88635^2 .

It is a cyclic number.

It is not a de Polignac number, because 21352561501 - 2¹⁵ = 21352528733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21352561541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676280750 + 10676280751.

It is an arithmetic number, because the mean of its divisors is an integer number (10676280751).

Almost surely, 2^21352561501 is an apocalyptic number.

It is an amenable number.

21352561501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21352561501 is an equidigital number, since it uses as much as digits as its factorization.

21352561501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9000, while the sum is 31.

The spelling of 21352561501 in words is "twenty-one billion, three hundred fifty-two million, five hundred sixty-one thousand, five hundred one".