1773721051421 has 4 divisors (see below), whose sum is σ = 1934968419744. Its totient is φ = 1612473683100.

The previous prime is 1773721051273. The next prime is 1773721051423. The reversal of 1773721051421 is 1241501273771.

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 a de Polignac number, because none of the positive numbers 2^k-1773721051421 is a prime.

It is a super-2 number, since 2×1773721051421² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1773721051423) 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, 80623684145 + ... + 80623684166.

It is an arithmetic number, because the mean of its divisors is an integer number (483742104936).

Almost surely, 2^{1773721051421} is an apocalyptic number.

1773721051421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1773721051421 is a deficient number, since it is larger than the sum of its proper divisors (161247368323).

1773721051421 is a wasteful number, since it uses less digits than its factorization.

1773721051421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161247368322.

The product of its (nonzero) digits is 82320, while the sum is 41.

The spelling of 1773721051421 in words is "one trillion, seven hundred seventy-three billion, seven hundred twenty-one million, fifty-one thousand, four hundred twenty-one".