1261291546 has 4 divisors (see below), whose sum is σ = 1891937322. Its totient is φ = 630645772.

The previous prime is 1261291531. The next prime is 1261291567. The reversal of 1261291546 is 6451921621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6451921621 = 373 ⋅17297377.

It can be written as a sum of positive squares in only one way, i.e., 1252381321 + 8910225 = 35389^2 + 2985^2 .

It is a super-2 number, since 2×1261291546² = 3181712728022140232, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315322885 + ... + 315322888.

Almost surely, 2^1261291546 is an apocalyptic number.

1261291546 is a deficient number, since it is larger than the sum of its proper divisors (630645776).

1261291546 is an equidigital number, since it uses as much as digits as its factorization.

1261291546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630645775.

The product of its digits is 25920, while the sum is 37.

The square root of 1261291546 is about 35514.6666322521. Note that the first 4 decimals coincide. The cubic root of 1261291546 is about 1080.4512134959.

The spelling of 1261291546 in words is "one billion, two hundred sixty-one million, two hundred ninety-one thousand, five hundred forty-six".