1242940161 has 4 divisors (see below), whose sum is σ = 1657253552. Its totient is φ = 828626772.

The previous prime is 1242940147. The next prime is 1242940277. The reversal of 1242940161 is 1610492421.

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 1242940161 - 2¹³ = 1242931969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242940561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207156691 + ... + 207156696.

It is an arithmetic number, because the mean of its divisors is an integer number (414313388).

Almost surely, 2^1242940161 is an apocalyptic number.

It is an amenable number.

1242940161 is a deficient number, since it is larger than the sum of its proper divisors (414313391).

1242940161 is an equidigital number, since it uses as much as digits as its factorization.

1242940161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414313390.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 1242940161 is about 35255.3564866390. The cubic root of 1242940161 is about 1075.1855200999.

The spelling of 1242940161 in words is "one billion, two hundred forty-two million, nine hundred forty thousand, one hundred sixty-one".