1645650243242 has 4 divisors (see below), whose sum is σ = 2468475364866. Its totient is φ = 822825121620.

The previous prime is 1645650243239. The next prime is 1645650243283. The reversal of 1645650243242 is 2423420565461.

It is a happy number.

It is a Cunningham number, because it is equal to 1282829²+1.

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., 1645650243241 + 1 = 1282829^2 + 1^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1645650243193 and 1645650243202.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411412560809 + ... + 411412560812.

Almost surely, 2^{1645650243242} is an apocalyptic number.

1645650243242 is a deficient number, since it is larger than the sum of its proper divisors (822825121624).

1645650243242 is an equidigital number, since it uses as much as digits as its factorization.

1645650243242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822825121623.

The product of its (nonzero) digits is 1382400, while the sum is 44.

The spelling of 1645650243242 in words is "one trillion, six hundred forty-five billion, six hundred fifty million, two hundred forty-three thousand, two hundred forty-two".