1242655745 has 4 divisors (see below), whose sum is σ = 1491186900. Its totient is φ = 994124592.

The previous prime is 1242655723. The next prime is 1242655747. The reversal of 1242655745 is 5475562421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5475562421 = 7 ⋅782223203.

It can be written as a sum of positive squares in 2 ways, for example, as 479128321 + 763527424 = 21889^2 + 27632^2 .

It is a cyclic number.

It is not a de Polignac number, because 1242655745 - 2⁸ = 1242655489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1242655747) 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, 124265570 + ... + 124265579.

It is an arithmetic number, because the mean of its divisors is an integer number (372796725).

Almost surely, 2^1242655745 is an apocalyptic number.

It is an amenable number.

1242655745 is a deficient number, since it is larger than the sum of its proper divisors (248531155).

1242655745 is an equidigital number, since it uses as much as digits as its factorization.

1242655745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248531154.

The product of its digits is 336000, while the sum is 41.

The square root of 1242655745 is about 35251.3225993012. The cubic root of 1242655745 is about 1075.1035040055.

The spelling of 1242655745 in words is "one billion, two hundred forty-two million, six hundred fifty-five thousand, seven hundred forty-five".