1961981944 has 32 divisors (see below), whose sum is σ = 3969131040. Its totient is φ = 903830400.

The previous prime is 1961981927. The next prime is 1961981953. The reversal of 1961981944 is 4491891691.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a junction number, because it is equal to n+sod(n) for n = 1961981891 and 1961981900.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38829 + ... + 73699.

It is an arithmetic number, because the mean of its divisors is an integer number (124035345).

Almost surely, 2^1961981944 is an apocalyptic number.

It is an amenable number.

1961981944 is an abundant number, since it is smaller than the sum of its proper divisors (2007149096).

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

1961981944 is a wasteful number, since it uses less digits than its factorization.

1961981944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35431 (or 35427 counting only the distinct ones).

The product of its digits is 559872, while the sum is 52.

The square root of 1961981944 is about 44294.2653624597. The cubic root of 1961981944 is about 1251.8866324485.

The spelling of 1961981944 in words is "one billion, nine hundred sixty-one million, nine hundred eighty-one thousand, nine hundred forty-four".