1643016229921 has 4 divisors (see below), whose sum is σ = 1792381341744. Its totient is φ = 1493651118100.

The previous prime is 1643016229909. The next prime is 1643016229937. The reversal of 1643016229921 is 1299226103461.

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 1643016229921 - 2⁹ = 1643016229409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643016229951) 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 in 3 ways as a sum of consecutive naturals, for example, 74682555895 + ... + 74682555916.

It is an arithmetic number, because the mean of its divisors is an integer number (448095335436).

Almost surely, 2^{1643016229921} is an apocalyptic number.

1643016229921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1643016229921 is a deficient number, since it is larger than the sum of its proper divisors (149365111823).

1643016229921 is a wasteful number, since it uses less digits than its factorization.

1643016229921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149365111822.

The product of its (nonzero) digits is 279936, while the sum is 46.

The spelling of 1643016229921 in words is "one trillion, six hundred forty-three billion, sixteen million, two hundred twenty-nine thousand, nine hundred twenty-one".