1897560721 has 21 divisors (see below), whose sum is σ = 2231387049. Its totient is φ = 1613673684.

The previous prime is 1897560661. The next prime is 1897560727. The reversal of 1897560721 is 1270657981.

It is a happy number.

The square root of 1897560721 is 43561.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1897560721 - 2⁷ = 1897560593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1897560727) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 14941360 + ... + 14941486.

Almost surely, 2^1897560721 is an apocalyptic number.

1897560721 is the 43561-st square number.

1897560721 is the 21781-st centered octagonal number.

It is an amenable number.

1897560721 is a deficient number, since it is larger than the sum of its proper divisors (333826328).

1897560721 is an frugal number, since it uses more digits than its factorization.

1897560721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 46.

The cubic root of 1897560721 is about 1238.0320677167.

The spelling of 1897560721 in words is "one billion, eight hundred ninety-seven million, five hundred sixty thousand, seven hundred twenty-one".