1245651749 has 4 divisors (see below), whose sum is σ = 1247338080. Its totient is φ = 1243965420.

The previous prime is 1245651689. The next prime is 1245651809. The reversal of 1245651749 is 9471565421.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9471565421 = 107 ⋅88519303.

It is an interprime number because it is at equal distance from previous prime (1245651689) and next prime (1245651809).

It is a cyclic number.

It is not a de Polignac number, because 1245651749 - 2⁸ = 1245651493 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 (1245654749) 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, 842057 + ... + 843534.

It is an arithmetic number, because the mean of its divisors is an integer number (311834520).

Almost surely, 2^1245651749 is an apocalyptic number.

It is an amenable number.

1245651749 is a deficient number, since it is larger than the sum of its proper divisors (1686331).

1245651749 is an equidigital number, since it uses as much as digits as its factorization.

1245651749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1686330.

The product of its digits is 302400, while the sum is 44.

The square root of 1245651749 is about 35293.7919328598. The cubic root of 1245651749 is about 1075.9668241661.

The spelling of 1245651749 in words is "one billion, two hundred forty-five million, six hundred fifty-one thousand, seven hundred forty-nine".