642727798 has 4 divisors (see below), whose sum is σ = 964091700. Its totient is φ = 321363898.

The previous prime is 642727759. The next prime is 642727817. The reversal of 642727798 is 897727246.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160681948 + ... + 160681951.

It is an arithmetic number, because the mean of its divisors is an integer number (241022925).

Almost surely, 2^642727798 is an apocalyptic number.

642727798 is a deficient number, since it is larger than the sum of its proper divisors (321363902).

642727798 is a wasteful number, since it uses less digits than its factorization.

642727798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321363901.

The product of its digits is 2370816, while the sum is 52.

The square root of 642727798 is about 25352.0767985583. The cubic root of 642727798 is about 862.9964870396.

It can be divided in two parts, 6427 and 27798, that added together give a square (34225 = 185²).

The spelling of 642727798 in words is "six hundred forty-two million, seven hundred twenty-seven thousand, seven hundred ninety-eight".