1720216851 has 32 divisors (see below), whose sum is σ = 2543063040. Its totient is φ = 1029419424.

The previous prime is 1720216843. The next prime is 1720216903. The reversal of 1720216851 is 1586120271.

It is not a de Polignac number, because 1720216851 - 2³ = 1720216843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1720216811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 134146 + ... + 146408.

It is an arithmetic number, because the mean of its divisors is an integer number (79470720).

Almost surely, 2^1720216851 is an apocalyptic number.

1720216851 is a deficient number, since it is larger than the sum of its proper divisors (822846189).

1720216851 is a wasteful number, since it uses less digits than its factorization.

1720216851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12415.

The product of its (nonzero) digits is 6720, while the sum is 33.

The square root of 1720216851 is about 41475.4969952139. The cubic root of 1720216851 is about 1198.1956333830.

The spelling of 1720216851 in words is "one billion, seven hundred twenty million, two hundred sixteen thousand, eight hundred fifty-one".