1671725381 has 2 divisors, whose sum is σ = 1671725382. Its totient is φ = 1671725380.

The previous prime is 1671725351. The next prime is 1671725423. The reversal of 1671725381 is 1835271761.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1051964356 + 619761025 = 32434^2 + 24895^2 .

It is an emirp because it is prime and its reverse (1835271761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1671725381 - 2¹⁸ = 1671463237 is a prime.

It is a super-2 number, since 2×1671725381² = 5589331498959190322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1671725351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 835862690 + 835862691.

It is an arithmetic number, because the mean of its divisors is an integer number (835862691).

Almost surely, 2^1671725381 is an apocalyptic number.

It is an amenable number.

1671725381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1671725381 is an equidigital number, since it uses as much as digits as its factorization.

1671725381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 41.

The square root of 1671725381 is about 40886.7384490375. The cubic root of 1671725381 is about 1186.8294437085.

The spelling of 1671725381 in words is "one billion, six hundred seventy-one million, seven hundred twenty-five thousand, three hundred eighty-one".