1261108558 has 16 divisors (see below), whose sum is σ = 2002405680. Its totient is φ = 594651456.

The previous prime is 1261108549. The next prime is 1261108567. The reversal of 1261108558 is 8558011621.

It is an interprime number because it is at equal distance from previous prime (1261108549) and next prime (1261108567).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 250335 + ... + 255322.

It is an arithmetic number, because the mean of its divisors is an integer number (125150355).

Almost surely, 2^1261108558 is an apocalyptic number.

1261108558 is a deficient number, since it is larger than the sum of its proper divisors (741297122).

1261108558 is a wasteful number, since it uses less digits than its factorization.

1261108558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505731.

The product of its (nonzero) digits is 19200, while the sum is 37.

The square root of 1261108558 is about 35512.0903073869. The cubic root of 1261108558 is about 1080.3989603988.

It can be divided in two parts, 1261108 and 558, that added together give a triangular number (1261666 = T₁₅₈₈).

The spelling of 1261108558 in words is "one billion, two hundred sixty-one million, one hundred eight thousand, five hundred fifty-eight".