21353535387031 has 2 divisors, whose sum is σ = 21353535387032. Its totient is φ = 21353535387030.

The previous prime is 21353535386923. The next prime is 21353535387043. The reversal of 21353535387031 is 13078353535312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21353535387031 - 2¹¹ = 21353535384983 is a prime.

It is a super-2 number, since 2×21353535387031² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21353539387031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676767693515 + 10676767693516.

It is an arithmetic number, because the mean of its divisors is an integer number (10676767693516).

Almost surely, 2^{21353535387031} is an apocalyptic number.

21353535387031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21353535387031 is an equidigital number, since it uses as much as digits as its factorization.

21353535387031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402000, while the sum is 49.

The spelling of 21353535387031 in words is "twenty-one trillion, three hundred fifty-three billion, five hundred thirty-five million, three hundred eighty-seven thousand, thirty-one".