18851957 has 2 divisors, whose sum is σ = 18851958. Its totient is φ = 18851956.

The previous prime is 18851951. The next prime is 18851969. The reversal of 18851957 is 75915881.

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., 11062276 + 7789681 = 3326^2 + 2791^2 .

It is a cyclic number.

It is not a de Polignac number, because 18851957 - 2⁶ = 18851893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18851951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9425978 + 9425979.

It is an arithmetic number, because the mean of its divisors is an integer number (9425979).

Almost surely, 2^18851957 is an apocalyptic number.

It is an amenable number.

18851957 is a deficient number, since it is larger than the sum of its proper divisors (1).

18851957 is an equidigital number, since it uses as much as digits as its factorization.

18851957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 44.

The square root of 18851957 is about 4341.8840380646. The cubic root of 18851957 is about 266.1453075722.

The spelling of 18851957 in words is "eighteen million, eight hundred fifty-one thousand, nine hundred fifty-seven".