7778217642 has 32 divisors (see below), whose sum is σ = 16822639680. Its totient is φ = 2383361280.

The previous prime is 7778217641. The next prime is 7778217659. The reversal of 7778217642 is 2467128777.

It is not an unprimeable number, because it can be changed into a prime (7778217641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188092 + ... + 225687.

It is an arithmetic number, because the mean of its divisors is an integer number (525707490).

Almost surely, 2^7778217642 is an apocalyptic number.

7778217642 is an abundant number, since it is smaller than the sum of its proper divisors (9044422038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7778217642 is a wasteful number, since it uses less digits than its factorization.

7778217642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414038.

The product of its digits is 1843968, while the sum is 51.

The square root of 7778217642 is about 88194.2041292964. The cubic root of 7778217642 is about 1981.3446671494.

The spelling of 7778217642 in words is "seven billion, seven hundred seventy-eight million, two hundred seventeen thousand, six hundred forty-two".