1961891550 has 96 divisors (see below), whose sum is σ = 5690707200. Its totient is φ = 495629280.

The previous prime is 1961891549. The next prime is 1961891567. The reversal of 1961891550 is 551981691.

1961891550 is a `hidden beast` number, since 1 + 9 + 6 + 1 + 8 + 91 + 550 = 666.

It is a super-2 number, since 2×1961891550² = 7698036907922805000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 1961891496 and 1961891505.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 12594 + ... + 63893.

It is an arithmetic number, because the mean of its divisors is an integer number (59278200).

Almost surely, 2^1961891550 is an apocalyptic number.

1961891550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1961891550 is an abundant number, since it is smaller than the sum of its proper divisors (3728815650).

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

1961891550 is a wasteful number, since it uses less digits than its factorization.

1961891550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76527 (or 76516 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 45.

The square root of 1961891550 is about 44293.2449703112. The cubic root of 1961891550 is about 1251.8674061794.

The spelling of 1961891550 in words is "one billion, nine hundred sixty-one million, eight hundred ninety-one thousand, five hundred fifty".