1681624541 has 2 divisors, whose sum is σ = 1681624542. Its totient is φ = 1681624540.

The previous prime is 1681624531. The next prime is 1681624559. The reversal of 1681624541 is 1454261861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1665456100 + 16168441 = 40810^2 + 4021^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681624541 - 2²⁶ = 1614515677 is a prime.

It is a super-2 number, since 2×1681624541² = 5655722193786921362, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1681624495 and 1681624504.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681624501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840812270 + 840812271.

It is an arithmetic number, because the mean of its divisors is an integer number (840812271).

Almost surely, 2^1681624541 is an apocalyptic number.

It is an amenable number.

1681624541 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681624541 is an equidigital number, since it uses as much as digits as its factorization.

1681624541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46080, while the sum is 38.

The square root of 1681624541 is about 41007.6156463650. The cubic root of 1681624541 is about 1189.1674474623.

The spelling of 1681624541 in words is "one billion, six hundred eighty-one million, six hundred twenty-four thousand, five hundred forty-one".