1961981316 has 72 divisors (see below), whose sum is σ = 5003107200. Its totient is φ = 648267840.

The previous prime is 1961981299. The next prime is 1961981317. The reversal of 1961981316 is 6131891691.

1961981316 is a `hidden beast` number, since 1 + 9 + 619 + 8 + 13 + 16 = 666.

It is not an unprimeable number, because it can be changed into a prime (1961981317) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2728405 + ... + 2729123.

It is an arithmetic number, because the mean of its divisors is an integer number (69487600).

Almost surely, 2^1961981316 is an apocalyptic number.

It is an amenable number.

1961981316 is an abundant number, since it is smaller than the sum of its proper divisors (3041125884).

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

1961981316 is a wasteful number, since it uses less digits than its factorization.

1961981316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1289 (or 1284 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 1961981316 is about 44294.2582735054. The cubic root of 1961981316 is about 1251.8864988786.

The spelling of 1961981316 in words is "one billion, nine hundred sixty-one million, nine hundred eighty-one thousand, three hundred sixteen".