1215942749 has 4 divisors (see below), whose sum is σ = 1389648864. Its totient is φ = 1042236636.

The previous prime is 1215942727. The next prime is 1215942809. The reversal of 1215942749 is 9472495121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1215942749 - 2²⁸ = 947507293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215942709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86853047 + ... + 86853060.

It is an arithmetic number, because the mean of its divisors is an integer number (347412216).

Almost surely, 2^1215942749 is an apocalyptic number.

It is an amenable number.

1215942749 is a deficient number, since it is larger than the sum of its proper divisors (173706115).

1215942749 is an equidigital number, since it uses as much as digits as its factorization.

1215942749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173706114.

The product of its digits is 181440, while the sum is 44.

The square root of 1215942749 is about 34870.3706461517. The cubic root of 1215942749 is about 1067.3439082760.

The spelling of 1215942749 in words is "one billion, two hundred fifteen million, nine hundred forty-two thousand, seven hundred forty-nine".