19391043210121 has 4 divisors (see below), whose sum is σ = 21153865320144. Its totient is φ = 17628221100100.

The previous prime is 19391043210053. The next prime is 19391043210139. The reversal of 19391043210121 is 12101234019391.

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 19391043210121 - 2²⁹ = 19390506339209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19391043213121) 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, 881411054995 + ... + 881411055016.

It is an arithmetic number, because the mean of its divisors is an integer number (5288466330036).

Almost surely, 2^{19391043210121} is an apocalyptic number.

19391043210121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19391043210121 is a deficient number, since it is larger than the sum of its proper divisors (1762822110023).

19391043210121 is a wasteful number, since it uses less digits than its factorization.

19391043210121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762822110022.

The product of its (nonzero) digits is 11664, while the sum is 37.

The spelling of 19391043210121 in words is "nineteen trillion, three hundred ninety-one billion, forty-three million, two hundred ten thousand, one hundred twenty-one".