1055556509 has 4 divisors (see below), whose sum is σ = 1206350304. Its totient is φ = 904762716.

The previous prime is 1055556499. The next prime is 1055556517. The reversal of 1055556509 is 9056555501.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9056555501 = 7 ⋅1293793643.

It is a cyclic number.

It is not a de Polignac number, because 1055556509 - 2⁸ = 1055556253 is a prime.

It is a super-2 number, since 2×1055556509² = 2228399087384534162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1055556539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75396887 + ... + 75396900.

It is an arithmetic number, because the mean of its divisors is an integer number (301587576).

Almost surely, 2^1055556509 is an apocalyptic number.

It is an amenable number.

1055556509 is a deficient number, since it is larger than the sum of its proper divisors (150793795).

1055556509 is an equidigital number, since it uses as much as digits as its factorization.

1055556509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150793794.

The product of its (nonzero) digits is 168750, while the sum is 41.

The square root of 1055556509 is about 32489.3291558936. The cubic root of 1055556509 is about 1018.1860972781.

The spelling of 1055556509 in words is "one billion, fifty-five million, five hundred fifty-six thousand, five hundred nine".