2578399556 has 6 divisors (see below), whose sum is σ = 4512199230. Its totient is φ = 1289199776.

The previous prime is 2578399517. The next prime is 2578399561. The reversal of 2578399556 is 6559938752.

It can be written as a sum of positive squares in only one way, i.e., 1641060100 + 937339456 = 40510^2 + 30616^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2578399495 and 2578399504.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322299941 + ... + 322299948.

It is an arithmetic number, because the mean of its divisors is an integer number (752033205).

Almost surely, 2^2578399556 is an apocalyptic number.

It is an amenable number.

2578399556 is a deficient number, since it is larger than the sum of its proper divisors (1933799674).

2578399556 is a wasteful number, since it uses less digits than its factorization.

2578399556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644599893 (or 644599891 counting only the distinct ones).

The product of its digits is 20412000, while the sum is 59.

The square root of 2578399556 is about 50777.9435975897. The cubic root of 2578399556 is about 1371.2503115011.

The spelling of 2578399556 in words is "two billion, five hundred seventy-eight million, three hundred ninety-nine thousand, five hundred fifty-six".