1961816931 has 12 divisors (see below), whose sum is σ = 2834867880. Its totient is φ = 1307355360.

The previous prime is 1961816929. The next prime is 1961816951. The reversal of 1961816931 is 1396181691.

1961816931 is a `hidden beast` number, since 19 + 618 + 16 + 9 + 3 + 1 = 666.

It is not a de Polignac number, because 1961816931 - 2¹ = 1961816929 is a prime.

It is a super-2 number, since 2×1961816931² = 7697451341516517522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1961816951) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19050 + ... + 65471.

It is an arithmetic number, because the mean of its divisors is an integer number (236238990).

Almost surely, 2^1961816931 is an apocalyptic number.

1961816931 is a deficient number, since it is larger than the sum of its proper divisors (873050949).

1961816931 is a wasteful number, since it uses less digits than its factorization.

1961816931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87106 (or 87103 counting only the distinct ones).

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

The square root of 1961816931 is about 44292.4026329573. The cubic root of 1961816931 is about 1251.8515347146.

The spelling of 1961816931 in words is "one billion, nine hundred sixty-one million, eight hundred sixteen thousand, nine hundred thirty-one".