1961978256 has 60 divisors (see below), whose sum is σ = 6275219392. Its totient is φ = 560564928.

The previous prime is 1961978231. The next prime is 1961978261. The reversal of 1961978256 is 6528791691.

1961978256 is a `hidden beast` number, since 19 + 619 + 7 + 8 + 2 + 5 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 972196 + ... + 974211.

Almost surely, 2^1961978256 is an apocalyptic number.

1961978256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1961978256 is an abundant number, since it is smaller than the sum of its proper divisors (4313241136).

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

1961978256 is a wasteful number, since it uses less digits than its factorization.

1961978256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1946428 (or 1946419 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The square root of 1961978256 is about 44294.2237317689. The cubic root of 1961978256 is about 1251.8858480443.

The spelling of 1961978256 in words is "one billion, nine hundred sixty-one million, nine hundred seventy-eight thousand, two hundred fifty-six".