1390391537778 has 48 divisors (see below), whose sum is σ = 3070575285336. Its totient is φ = 454574545920.

The previous prime is 1390391537671. The next prime is 1390391537831. The reversal of 1390391537778 is 8777351930931.

1390391537778 is a `hidden beast` number, since 1 + 3 + 9 + 0 + 3 + 91 + 537 + 7 + 7 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1227169881729 + 163221656049 = 1107777^2 + 404007^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1406025 + ... + 2181212.

Almost surely, 2^{1390391537778} is an apocalyptic number.

1390391537778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1390391537778 is an abundant number, since it is smaller than the sum of its proper divisors (1680183747558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1390391537778 is a wasteful number, since it uses less digits than its factorization.

1390391537778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3587659 (or 3587656 counting only the distinct ones).

The product of its (nonzero) digits is 30005640, while the sum is 63.

The spelling of 1390391537778 in words is "one trillion, three hundred ninety billion, three hundred ninety-one million, five hundred thirty-seven thousand, seven hundred seventy-eight".