21515740435127 has 2 divisors, whose sum is σ = 21515740435128. Its totient is φ = 21515740435126.

The previous prime is 21515740435103. The next prime is 21515740435157. The reversal of 21515740435127 is 72153404751512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21515740435127 - 2¹⁴ = 21515740418743 is a prime.

It is a super-2 number, since 2×21515740435127² (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 (21515740435157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10757870217563 + 10757870217564.

It is an arithmetic number, because the mean of its divisors is an integer number (10757870217564).

Almost surely, 2^{21515740435127} is an apocalyptic number.

21515740435127 is a deficient number, since it is larger than the sum of its proper divisors (1).

21515740435127 is an equidigital number, since it uses as much as digits as its factorization.

21515740435127 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1176000, while the sum is 47.

The spelling of 21515740435127 in words is "twenty-one trillion, five hundred fifteen billion, seven hundred forty million, four hundred thirty-five thousand, one hundred twenty-seven".