258166621 has 2 divisors, whose sum is σ = 258166622. Its totient is φ = 258166620.

The previous prime is 258166619. The next prime is 258166633. The reversal of 258166621 is 126661852.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132480100 + 125686521 = 11510^2 + 11211^2 .

It is a cyclic number.

It is not a de Polignac number, because 258166621 - 2¹ = 258166619 is a prime.

Together with 258166619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (258166121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129083310 + 129083311.

It is an arithmetic number, because the mean of its divisors is an integer number (129083311).

Almost surely, 2^258166621 is an apocalyptic number.

It is an amenable number.

258166621 is a deficient number, since it is larger than the sum of its proper divisors (1).

258166621 is an equidigital number, since it uses as much as digits as its factorization.

258166621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 37.

The square root of 258166621 is about 16067.5642522443. The cubic root of 258166621 is about 636.7466911767.

The spelling of 258166621 in words is "two hundred fifty-eight million, one hundred sixty-six thousand, six hundred twenty-one".