1681450221 has 16 divisors (see below), whose sum is σ = 2505400128. Its totient is φ = 994204800.

The previous prime is 1681450217. The next prime is 1681450223. The reversal of 1681450221 is 1220541861.

1681450221 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1681450221 - 2² = 1681450217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681450223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 620026 + ... + 622731.

It is an arithmetic number, because the mean of its divisors is an integer number (156587508).

Almost surely, 2^1681450221 is an apocalyptic number.

1681450221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1681450221 is a deficient number, since it is larger than the sum of its proper divisors (823949907).

1681450221 is a wasteful number, since it uses less digits than its factorization.

1681450221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1242812.

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 1681450221 is about 41005.4901324201. The cubic root of 1681450221 is about 1189.1263556831.

The spelling of 1681450221 in words is "one billion, six hundred eighty-one million, four hundred fifty thousand, two hundred twenty-one".