1381656528 has 150 divisors (see below), whose sum is σ = 4652012706. Its totient is φ = 394740864.

The previous prime is 1381656511. The next prime is 1381656557. The reversal of 1381656528 is 8256561831.

1381656528 is a `hidden beast` number, since 1 + 3 + 81 + 6 + 565 + 2 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1353651264 + 28005264 = 36792^2 + 5292^2 .

It is a super-2 number, since 2×1381656528² = 3817949522730029568, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 52626 + ... + 74382.

Almost surely, 2^1381656528 is an apocalyptic number.

1381656528 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1381656528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2326006353).

1381656528 is an abundant number, since it is smaller than the sum of its proper divisors (3270356178).

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

1381656528 is a wasteful number, since it uses less digits than its factorization.

1381656528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21791 (or 21769 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 1381656528 is about 37170.6406724447. The cubic root of 1381656528 is about 1113.7815798956.

The spelling of 1381656528 in words is "one billion, three hundred eighty-one million, six hundred fifty-six thousand, five hundred twenty-eight".