1721125641 has 4 divisors (see below), whose sum is σ = 2294834192. Its totient is φ = 1147417092.

The previous prime is 1721125631. The next prime is 1721125643. The reversal of 1721125641 is 1465211271.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1465211271 = 3 ⋅488403757.

It is not a de Polignac number, because 1721125641 - 2⁷ = 1721125513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1721125599 and 1721125608.

It is not an unprimeable number, because it can be changed into a prime (1721125643) 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, 286854271 + ... + 286854276.

It is an arithmetic number, because the mean of its divisors is an integer number (573708548).

Almost surely, 2^1721125641 is an apocalyptic number.

It is an amenable number.

1721125641 is a deficient number, since it is larger than the sum of its proper divisors (573708551).

1721125641 is an equidigital number, since it uses as much as digits as its factorization.

1721125641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573708550.

The product of its digits is 3360, while the sum is 30.

The square root of 1721125641 is about 41486.4512943684. The cubic root of 1721125641 is about 1198.4065983569.

The spelling of 1721125641 in words is "one billion, seven hundred twenty-one million, one hundred twenty-five thousand, six hundred forty-one".