1243937645 has 6 divisors (see below), whose sum is σ = 1492819818. Its totient is φ = 995087024.

The previous prime is 1243937627. The next prime is 1243937659. The reversal of 1243937645 is 5467393421.

It can be written as a sum of positive squares in 3 ways, for example, as 196056004 + 1047881641 = 14002^2 + 32371^2 .

It is not a de Polignac number, because 1243937645 - 2¹⁶ = 1243872109 is a prime.

It is a super-3 number, since 3×1243937645³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1243937596 and 1243937605.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 70979 + ... + 86751.

It is an arithmetic number, because the mean of its divisors is an integer number (248803303).

Almost surely, 2^1243937645 is an apocalyptic number.

It is an amenable number.

1243937645 is a deficient number, since it is larger than the sum of its proper divisors (248882173).

1243937645 is an frugal number, since it uses more digits than its factorization.

1243937645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31551 (or 15778 counting only the distinct ones).

The product of its digits is 544320, while the sum is 44.

The square root of 1243937645 is about 35269.5002091042. The cubic root of 1243937645 is about 1075.4730623913.

The spelling of 1243937645 in words is "one billion, two hundred forty-three million, nine hundred thirty-seven thousand, six hundred forty-five".