21359309501 has 2 divisors, whose sum is σ = 21359309502. Its totient is φ = 21359309500.

The previous prime is 21359309459. The next prime is 21359309533. The reversal of 21359309501 is 10590395312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11424403225 + 9934906276 = 106885^2 + 99674^2 .

It is a cyclic number.

It is not a de Polignac number, because 21359309501 - 2¹⁸ = 21359047357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21359309581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10679654750 + 10679654751.

It is an arithmetic number, because the mean of its divisors is an integer number (10679654751).

Almost surely, 2^21359309501 is an apocalyptic number.

It is an amenable number.

21359309501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21359309501 is an equidigital number, since it uses as much as digits as its factorization.

21359309501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36450, while the sum is 38.

The spelling of 21359309501 in words is "twenty-one billion, three hundred fifty-nine million, three hundred nine thousand, five hundred one".