642378277 has 4 divisors (see below), whose sum is σ = 676187680. Its totient is φ = 608568876.

The previous prime is 642378271. The next prime is 642378287. The reversal of 642378277 is 772873246.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 772873246 = 2 ⋅386436623.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642378277 is a prime.

It is a super-2 number, since 2×642378277² = 825299701522977458, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642378271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16904673 + ... + 16904710.

It is an arithmetic number, because the mean of its divisors is an integer number (169046920).

Almost surely, 2^642378277 is an apocalyptic number.

It is an amenable number.

642378277 is a deficient number, since it is larger than the sum of its proper divisors (33809403).

642378277 is a wasteful number, since it uses less digits than its factorization.

642378277 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33809402.

The product of its digits is 790272, while the sum is 46.

The square root of 642378277 is about 25345.1825205501. The cubic root of 642378277 is about 862.8400236607.

The spelling of 642378277 in words is "six hundred forty-two million, three hundred seventy-eight thousand, two hundred seventy-seven".