1291749442 has 4 divisors (see below), whose sum is σ = 1937624166. Its totient is φ = 645874720.

The previous prime is 1291749427. The next prime is 1291749451. The reversal of 1291749442 is 2449471921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1136970961 + 154778481 = 33719^2 + 12441^2 .

It is a super-2 number, since 2×1291749442² = 3337233241814622728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322937359 + ... + 322937362.

Almost surely, 2^1291749442 is an apocalyptic number.

1291749442 is a deficient number, since it is larger than the sum of its proper divisors (645874724).

1291749442 is an equidigital number, since it uses as much as digits as its factorization.

1291749442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645874723.

The product of its digits is 145152, while the sum is 43.

The square root of 1291749442 is about 35940.9159872143. The cubic root of 1291749442 is about 1089.0791094161.

The spelling of 1291749442 in words is "one billion, two hundred ninety-one million, seven hundred forty-nine thousand, four hundred forty-two".