642769779 has 16 divisors (see below), whose sum is σ = 936714240. Its totient is φ = 390295680.

The previous prime is 642769769. The next prime is 642769783. The reversal of 642769779 is 977967246.

It is not a de Polignac number, because 642769779 - 2¹¹ = 642767731 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642769739) 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, 201699 + ... + 204860.

It is an arithmetic number, because the mean of its divisors is an integer number (58544640).

Almost surely, 2^642769779 is an apocalyptic number.

642769779 is a deficient number, since it is larger than the sum of its proper divisors (293944461).

642769779 is a wasteful number, since it uses less digits than its factorization.

642769779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406610.

The product of its digits is 8001504, while the sum is 57.

The square root of 642769779 is about 25352.9047448216. The cubic root of 642769779 is about 863.0152760546.

The spelling of 642769779 in words is "six hundred forty-two million, seven hundred sixty-nine thousand, seven hundred seventy-nine".