21512501124061 has 2 divisors, whose sum is σ = 21512501124062. Its totient is φ = 21512501124060.

The previous prime is 21512501124041. The next prime is 21512501124143. The reversal of 21512501124061 is 16042110521512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19647774321561 + 1864726802500 = 4432581^2 + 1365550^2 .

It is a cyclic number.

It is not a de Polignac number, because 21512501124061 - 2⁵ = 21512501124029 is a prime.

It is a super-2 number, since 2×21512501124061² (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 (21512501124001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10756250562030 + 10756250562031.

It is an arithmetic number, because the mean of its divisors is an integer number (10756250562031).

Almost surely, 2^{21512501124061} is an apocalyptic number.

It is an amenable number.

21512501124061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21512501124061 is an equidigital number, since it uses as much as digits as its factorization.

21512501124061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4800, while the sum is 31.

Adding to 21512501124061 its reverse (16042110521512), we get a palindrome (37554611645573).

The spelling of 21512501124061 in words is "twenty-one trillion, five hundred twelve billion, five hundred one million, one hundred twenty-four thousand, sixty-one".