1921729828801 has 4 divisors (see below), whose sum is σ = 1927909024704. Its totient is φ = 1915550632900.

The previous prime is 1921729828783. The next prime is 1921729828807. The reversal of 1921729828801 is 1088289271291.

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 1921729828801 - 2²³ = 1921721440193 is a prime.

It is a super-3 number, since 3×1921729828801³ (a number of 38 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1921729828807) 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, 3089597485 + ... + 3089598106.

It is an arithmetic number, because the mean of its divisors is an integer number (481977256176).

Almost surely, 2^{1921729828801} is an apocalyptic number.

It is an amenable number.

1921729828801 is a deficient number, since it is larger than the sum of its proper divisors (6179195903).

1921729828801 is an equidigital number, since it uses as much as digits as its factorization.

1921729828801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6179195902.

The product of its (nonzero) digits is 2322432, while the sum is 58.

The spelling of 1921729828801 in words is "one trillion, nine hundred twenty-one billion, seven hundred twenty-nine million, eight hundred twenty-eight thousand, eight hundred one".