127519251721 has 2 divisors, whose sum is σ = 127519251722. Its totient is φ = 127519251720.

The previous prime is 127519251707. The next prime is 127519251737. The reversal of 127519251721 is 127152915721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 116690560000 + 10828691721 = 341600^2 + 104061^2 .

It is a cyclic number.

It is not a de Polignac number, because 127519251721 - 2¹⁷ = 127519120649 is a prime.

It is a super-2 number, since 2×127519251721² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (127519251751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63759625860 + 63759625861.

It is an arithmetic number, because the mean of its divisors is an integer number (63759625861).

Almost surely, 2^127519251721 is an apocalyptic number.

It is an amenable number.

127519251721 is a deficient number, since it is larger than the sum of its proper divisors (1).

127519251721 is an equidigital number, since it uses as much as digits as its factorization.

127519251721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 88200, while the sum is 43.

The spelling of 127519251721 in words is "one hundred twenty-seven billion, five hundred nineteen million, two hundred fifty-one thousand, seven hundred twenty-one".