1245555778 has 8 divisors (see below), whose sum is σ = 1868771772. Its totient is φ = 622631856.

The previous prime is 1245555763. The next prime is 1245555797. The reversal of 1245555778 is 8775555421.

It can be written as a sum of positive squares in 2 ways, for example, as 1203604249 + 41951529 = 34693^2 + 6477^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1245555778² = 3102818392218370568, which contains 22 as substring.

It is a plaindrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62025 + ... + 79612.

Almost surely, 2^1245555778 is an apocalyptic number.

1245555778 is a deficient number, since it is larger than the sum of its proper divisors (623215994).

1245555778 is a wasteful number, since it uses less digits than its factorization.

1245555778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146036.

The product of its digits is 1960000, while the sum is 49.

The square root of 1245555778 is about 35292.4323049574. The cubic root of 1245555778 is about 1075.9391909039.

The spelling of 1245555778 in words is "one billion, two hundred forty-five million, five hundred fifty-five thousand, seven hundred seventy-eight".