1728661641 has 12 divisors (see below), whose sum is σ = 2681189712. Its totient is φ = 987806568.

The previous prime is 1728661631. The next prime is 1728661679. The reversal of 1728661641 is 1461668271.

It is not a de Polignac number, because 1728661641 - 2²² = 1724467337 is a prime.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1728661593 and 1728661602.

It is not an unprimeable number, because it can be changed into a prime (1728661601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5879655 + ... + 5879948.

It is an arithmetic number, because the mean of its divisors is an integer number (223432476).

Almost surely, 2^1728661641 is an apocalyptic number.

It is an amenable number.

1728661641 is a deficient number, since it is larger than the sum of its proper divisors (952528071).

1728661641 is a wasteful number, since it uses less digits than its factorization.

1728661641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11759620 (or 11759613 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 1728661641 is about 41577.1769243656. The cubic root of 1728661641 is about 1200.1531380953.

The spelling of 1728661641 in words is "one billion, seven hundred twenty-eight million, six hundred sixty-one thousand, six hundred forty-one".