7878692644 has 9 divisors (see below), whose sum is σ = 13788022801. Its totient is φ = 3939257560.

The previous prime is 7878692639. The next prime is 7878692651. The reversal of 7878692644 is 4462968787.

The square root of 7878692644 is 88762.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3095587044 + 4783105600 = 55638^2 + 69160^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 155334 + ... + 199714.

Almost surely, 2^7878692644 is an apocalyptic number.

7878692644 is the 88762-nd square number.

It is an amenable number.

7878692644 is a deficient number, since it is larger than the sum of its proper divisors (5909330157).

7878692644 is an frugal number, since it uses more digits than its factorization.

7878692644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88766 (or 44383 counting only the distinct ones).

The product of its digits is 32514048, while the sum is 61.

The cubic root of 7878692644 is about 1989.8395234346.

The spelling of 7878692644 in words is "seven billion, eight hundred seventy-eight million, six hundred ninety-two thousand, six hundred forty-four".