21506137333607 has 2 divisors, whose sum is σ = 21506137333608. Its totient is φ = 21506137333606.

The previous prime is 21506137333561. The next prime is 21506137333717. The reversal of 21506137333607 is 70633373160512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21506137333607 - 2¹² = 21506137329511 is a prime.

It is a super-2 number, since 2×21506137333607² (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 (21506137333007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10753068666803 + 10753068666804.

It is an arithmetic number, because the mean of its divisors is an integer number (10753068666804).

Almost surely, 2^{21506137333607} is an apocalyptic number.

21506137333607 is a deficient number, since it is larger than the sum of its proper divisors (1).

21506137333607 is an equidigital number, since it uses as much as digits as its factorization.

21506137333607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1428840, while the sum is 47.

The spelling of 21506137333607 in words is "twenty-one trillion, five hundred six billion, one hundred thirty-seven million, three hundred thirty-three thousand, six hundred seven".