1251201535081 has 2 divisors, whose sum is σ = 1251201535082. Its totient is φ = 1251201535080.

The previous prime is 1251201535027. The next prime is 1251201535139. The reversal of 1251201535081 is 1805351021521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1222552587481 + 28648947600 = 1105691^2 + 169260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251201535081 - 2¹¹ = 1251201533033 is a prime.

It is a super-2 number, since 2×1251201535081² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1251201535021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625600767540 + 625600767541.

It is an arithmetic number, because the mean of its divisors is an integer number (625600767541).

Almost surely, 2^{1251201535081} is an apocalyptic number.

It is an amenable number.

1251201535081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251201535081 is an equidigital number, since it uses as much as digits as its factorization.

1251201535081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12000, while the sum is 34.

The spelling of 1251201535081 in words is "one trillion, two hundred fifty-one billion, two hundred one million, five hundred thirty-five thousand, eighty-one".