1971357149 has 2 divisors, whose sum is σ = 1971357150. Its totient is φ = 1971357148.

The previous prime is 1971357127. The next prime is 1971357173. The reversal of 1971357149 is 9417531791.

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., 1929844900 + 41512249 = 43930^2 + 6443^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971357149 - 2¹² = 1971353053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1971357649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985678574 + 985678575.

It is an arithmetic number, because the mean of its divisors is an integer number (985678575).

Almost surely, 2^1971357149 is an apocalyptic number.

It is an amenable number.

1971357149 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971357149 is an equidigital number, since it uses as much as digits as its factorization.

1971357149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 238140, while the sum is 47.

The square root of 1971357149 is about 44399.9678941325. The cubic root of 1971357149 is about 1253.8774847727.

The spelling of 1971357149 in words is "one billion, nine hundred seventy-one million, three hundred fifty-seven thousand, one hundred forty-nine".