1388512261 has 2 divisors, whose sum is σ = 1388512262. Its totient is φ = 1388512260.

The previous prime is 1388512243. The next prime is 1388512271. The reversal of 1388512261 is 1622158831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1318053025 + 70459236 = 36305^2 + 8394^2 .

It is a cyclic number.

It is not a de Polignac number, because 1388512261 - 2¹⁵ = 1388479493 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1388512261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1388512201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 694256130 + 694256131.

It is an arithmetic number, because the mean of its divisors is an integer number (694256131).

Almost surely, 2^1388512261 is an apocalyptic number.

It is an amenable number.

1388512261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1388512261 is an equidigital number, since it uses as much as digits as its factorization.

1388512261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 37.

The square root of 1388512261 is about 37262.7462890217. The cubic root of 1388512261 is about 1115.6207235054.

The spelling of 1388512261 in words is "one billion, three hundred eighty-eight million, five hundred twelve thousand, two hundred sixty-one".