1249138081 has 2 divisors, whose sum is σ = 1249138082. Its totient is φ = 1249138080.

The previous prime is 1249138069. The next prime is 1249138117. The reversal of 1249138081 is 1808319421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1247219856 + 1918225 = 35316^2 + 1385^2 .

It is a cyclic number.

It is not a de Polignac number, because 1249138081 - 2⁹ = 1249137569 is a prime.

It is a super-2 number, since 2×1249138081² = 3120691890808725122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1249138081.

It is not a weakly prime, because it can be changed into another prime (1249138181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624569040 + 624569041.

It is an arithmetic number, because the mean of its divisors is an integer number (624569041).

Almost surely, 2^1249138081 is an apocalyptic number.

It is an amenable number.

1249138081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249138081 is an equidigital number, since it uses as much as digits as its factorization.

1249138081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 1249138081 is about 35343.1475819571. The cubic root of 1249138081 is about 1076.9696949936.

The spelling of 1249138081 in words is "one billion, two hundred forty-nine million, one hundred thirty-eight thousand, eighty-one".