1961889947 has 16 divisors (see below), whose sum is σ = 2092460832. Its totient is φ = 1833062400.

The previous prime is 1961889931. The next prime is 1961889967. The reversal of 1961889947 is 7499881691.

It is not a de Polignac number, because 1961889947 - 2⁴ = 1961889931 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1961889947.

It is not an unprimeable number, because it can be changed into a prime (1961889907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1632947 + ... + 1634147.

It is an arithmetic number, because the mean of its divisors is an integer number (130778802).

Almost surely, 2^1961889947 is an apocalyptic number.

1961889947 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1961889947 is a deficient number, since it is larger than the sum of its proper divisors (130570885).

1961889947 is a wasteful number, since it uses less digits than its factorization.

1961889947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1838.

The product of its digits is 7838208, while the sum is 62.

The square root of 1961889947 is about 44293.2268749975. The cubic root of 1961889947 is about 1251.8670652255.

The spelling of 1961889947 in words is "one billion, nine hundred sixty-one million, eight hundred eighty-nine thousand, nine hundred forty-seven".