21137502433 has 2 divisors, whose sum is σ = 21137502434. Its totient is φ = 21137502432.

The previous prime is 21137502391. The next prime is 21137502461. The reversal of 21137502433 is 33420573112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13281871009 + 7855631424 = 115247^2 + 88632^2 .

It is a cyclic number.

It is not a de Polignac number, because 21137502433 - 2¹⁷ = 21137371361 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21137502395 and 21137502404.

It is not a weakly prime, because it can be changed into another prime (21137502493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10568751216 + 10568751217.

It is an arithmetic number, because the mean of its divisors is an integer number (10568751217).

Almost surely, 2^21137502433 is an apocalyptic number.

It is an amenable number.

21137502433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21137502433 is an equidigital number, since it uses as much as digits as its factorization.

21137502433 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 31.

The spelling of 21137502433 in words is "twenty-one billion, one hundred thirty-seven million, five hundred two thousand, four hundred thirty-three".