1961554999 has 2 divisors, whose sum is σ = 1961555000. Its totient is φ = 1961554998.

The previous prime is 1961554997. The next prime is 1961555021. The reversal of 1961554999 is 9994551691.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1961554999 - 2¹ = 1961554997 is a prime.

Together with 1961554997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1961554993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980777499 + 980777500.

It is an arithmetic number, because the mean of its divisors is an integer number (980777500).

Almost surely, 2^1961554999 is an apocalyptic number.

1961554999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961554999 is an equidigital number, since it uses as much as digits as its factorization.

1961554999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3936600, while the sum is 58.

The square root of 1961554999 is about 44289.4456840453. The cubic root of 1961554999 is about 1251.7958185797.

The spelling of 1961554999 in words is "one billion, nine hundred sixty-one million, five hundred fifty-four thousand, nine hundred ninety-nine".