640450466542 has 4 divisors (see below), whose sum is σ = 960675699816. Its totient is φ = 320225233270.

The previous prime is 640450466489. The next prime is 640450466543. The reversal of 640450466542 is 245664054046.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 245664054046 = 2 ⋅122832027023.

It is a super-2 number, since 2×640450466542² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 640450466492 and 640450466501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640450466543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160112616634 + ... + 160112616637.

It is an arithmetic number, because the mean of its divisors is an integer number (240168924954).

Almost surely, 2^640450466542 is an apocalyptic number.

640450466542 is a deficient number, since it is larger than the sum of its proper divisors (320225233274).

640450466542 is a wasteful number, since it uses less digits than its factorization.

640450466542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320225233273.

The product of its (nonzero) digits is 2764800, while the sum is 46.

The spelling of 640450466542 in words is "six hundred forty billion, four hundred fifty million, four hundred sixty-six thousand, five hundred forty-two".