1881721463 has 4 divisors (see below), whose sum is σ = 1946608440. Its totient is φ = 1816834488.

The previous prime is 1881721399. The next prime is 1881721481. The reversal of 1881721463 is 3641271881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3641271881 = 13 ⋅280097837.

It is a cyclic number.

It is not a de Polignac number, because 1881721463 - 2⁶ = 1881721399 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1881721463.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1881711463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32443445 + ... + 32443502.

It is an arithmetic number, because the mean of its divisors is an integer number (486652110).

Almost surely, 2^1881721463 is an apocalyptic number.

1881721463 is a deficient number, since it is larger than the sum of its proper divisors (64886977).

1881721463 is an equidigital number, since it uses as much as digits as its factorization.

1881721463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64886976.

The product of its digits is 64512, while the sum is 41.

The square root of 1881721463 is about 43378.8135268820. The cubic root of 1881721463 is about 1234.5777513692.

The spelling of 1881721463 in words is "one billion, eight hundred eighty-one million, seven hundred twenty-one thousand, four hundred sixty-three".