1248990261 has 4 divisors (see below), whose sum is σ = 1665320352. Its totient is φ = 832660172.

The previous prime is 1248990247. The next prime is 1248990277. The reversal of 1248990261 is 1620998421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1248990261 - 2¹³ = 1248982069 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1248990661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208165041 + ... + 208165046.

It is an arithmetic number, because the mean of its divisors is an integer number (416330088).

Almost surely, 2^1248990261 is an apocalyptic number.

It is an amenable number.

1248990261 is a deficient number, since it is larger than the sum of its proper divisors (416330091).

1248990261 is an equidigital number, since it uses as much as digits as its factorization.

1248990261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416330090.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 1248990261 is about 35341.0563084920. The cubic root of 1248990261 is about 1076.9272113155.

The spelling of 1248990261 in words is "one billion, two hundred forty-eight million, nine hundred ninety thousand, two hundred sixty-one".