1955663381 has 4 divisors (see below), whose sum is σ = 2235043872. Its totient is φ = 1676282892.

The previous prime is 1955663371. The next prime is 1955663399. The reversal of 1955663381 is 1833665591.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1955663381 - 2⁶ = 1955663317 is a prime.

It is a super-2 number, since 2×1955663381² = 7649238519568702322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1955663321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139690235 + ... + 139690248.

It is an arithmetic number, because the mean of its divisors is an integer number (558760968).

Almost surely, 2^1955663381 is an apocalyptic number.

It is an amenable number.

1955663381 is a deficient number, since it is larger than the sum of its proper divisors (279380491).

1955663381 is an equidigital number, since it uses as much as digits as its factorization.

1955663381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279380490.

The product of its digits is 583200, while the sum is 47.

The square root of 1955663381 is about 44222.8830019030. The cubic root of 1955663381 is about 1250.5412868530.

The spelling of 1955663381 in words is "one billion, nine hundred fifty-five million, six hundred sixty-three thousand, three hundred eighty-one".