149195861 has 2 divisors, whose sum is σ = 149195862. Its totient is φ = 149195860.

The previous prime is 149195857. The next prime is 149195863. The reversal of 149195861 is 168591941.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 146555236 + 2640625 = 12106^2 + 1625^2 .

It is a cyclic number.

It is not a de Polignac number, because 149195861 - 2² = 149195857 is a prime.

Together with 149195863, 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 (149195863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74597930 + 74597931.

It is an arithmetic number, because the mean of its divisors is an integer number (74597931).

Almost surely, 2^149195861 is an apocalyptic number.

It is an amenable number.

149195861 is a deficient number, since it is larger than the sum of its proper divisors (1).

149195861 is an equidigital number, since it uses as much as digits as its factorization.

149195861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 44.

The square root of 149195861 is about 12214.5757601318. The cubic root of 149195861 is about 530.3781103924.

The spelling of 149195861 in words is "one hundred forty-nine million, one hundred ninety-five thousand, eight hundred sixty-one".