1961464661 has 4 divisors (see below), whose sum is σ = 2112346572. Its totient is φ = 1810582752.

The previous prime is 1961464657. The next prime is 1961464669. The reversal of 1961464661 is 1664641691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1043677636 + 917787025 = 32306^2 + 30295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961464661 - 2² = 1961464657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1961464669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75440936 + ... + 75440961.

It is an arithmetic number, because the mean of its divisors is an integer number (528086643).

Almost surely, 2^1961464661 is an apocalyptic number.

It is an amenable number.

1961464661 is a deficient number, since it is larger than the sum of its proper divisors (150881911).

1961464661 is a wasteful number, since it uses less digits than its factorization.

1961464661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150881910.

The product of its digits is 186624, while the sum is 44.

The square root of 1961464661 is about 44288.4258130722. The cubic root of 1961464661 is about 1251.7766014336.

The spelling of 1961464661 in words is "one billion, nine hundred sixty-one million, four hundred sixty-four thousand, six hundred sixty-one".