642743156 has 24 divisors (see below), whose sum is σ = 1230376224. Its totient is φ = 291365280.

The previous prime is 642743149. The next prime is 642743159. The reversal of 642743156 is 651347246.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642743159) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3170 + ... + 35993.

It is an arithmetic number, because the mean of its divisors is an integer number (51265676).

Almost surely, 2^642743156 is an apocalyptic number.

It is an amenable number.

642743156 is a deficient number, since it is larger than the sum of its proper divisors (587633068).

642743156 is a wasteful number, since it uses less digits than its factorization.

642743156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39551 (or 39549 counting only the distinct ones).

The product of its digits is 120960, while the sum is 38.

The square root of 642743156 is about 25352.3796910665. The cubic root of 642743156 is about 863.0033607605.

The spelling of 642743156 in words is "six hundred forty-two million, seven hundred forty-three thousand, one hundred fifty-six".