1261405477 has 2 divisors, whose sum is σ = 1261405478. Its totient is φ = 1261405476.

The previous prime is 1261405367. The next prime is 1261405487. The reversal of 1261405477 is 7745041621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1257837156 + 3568321 = 35466^2 + 1889^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261405477 - 2¹⁵ = 1261372709 is a prime.

It is a super-2 number, since 2×1261405477² = 3182287554811195058, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261405487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630702738 + 630702739.

It is an arithmetic number, because the mean of its divisors is an integer number (630702739).

Almost surely, 2^1261405477 is an apocalyptic number.

It is an amenable number.

1261405477 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261405477 is an equidigital number, since it uses as much as digits as its factorization.

1261405477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47040, while the sum is 37.

The square root of 1261405477 is about 35516.2705953201. The cubic root of 1261405477 is about 1080.4837444840.

The spelling of 1261405477 in words is "one billion, two hundred sixty-one million, four hundred five thousand, four hundred seventy-seven".