1961121949903 has 8 divisors (see below), whose sum is σ = 1973186345088. Its totient is φ = 1949061378264.

The previous prime is 1961121949877. The next prime is 1961121949907. The reversal of 1961121949903 is 3099491211691.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1961121949903 - 2³³ = 1952532015311 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 (1961121949907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76500 + ... + 1981942.

It is an arithmetic number, because the mean of its divisors is an integer number (246648293136).

Almost surely, 2^{1961121949903} is an apocalyptic number.

1961121949903 is a deficient number, since it is larger than the sum of its proper divisors (12064395185).

1961121949903 is a wasteful number, since it uses less digits than its factorization.

1961121949903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1911773.

The product of its (nonzero) digits is 944784, while the sum is 55.

The spelling of 1961121949903 in words is "one trillion, nine hundred sixty-one billion, one hundred twenty-one million, nine hundred forty-nine thousand, nine hundred three".