1681420061 has 2 divisors, whose sum is σ = 1681420062. Its totient is φ = 1681420060.

The previous prime is 1681420051. The next prime is 1681420063. The reversal of 1681420061 is 1600241861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1680508036 + 912025 = 40994^2 + 955^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681420061 - 2¹⁸ = 1681157917 is a prime.

Together with 1681420063, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681420063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840710030 + 840710031.

It is an arithmetic number, because the mean of its divisors is an integer number (840710031).

Almost surely, 2^1681420061 is an apocalyptic number.

It is an amenable number.

1681420061 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681420061 is an equidigital number, since it uses as much as digits as its factorization.

1681420061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 1681420061 is about 41005.1223751375. The cubic root of 1681420061 is about 1189.1192458948.

The spelling of 1681420061 in words is "one billion, six hundred eighty-one million, four hundred twenty thousand, sixty-one".