640537154 has 4 divisors (see below), whose sum is σ = 960805734. Its totient is φ = 320268576.

The previous prime is 640537153. The next prime is 640537187. The reversal of 640537154 is 451735046.

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

It can be written as a sum of positive squares in only one way, i.e., 616379929 + 24157225 = 24827^2 + 4915^2 .

It is not an unprimeable number, because it can be changed into a prime (640537153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160134287 + ... + 160134290.

Almost surely, 2^640537154 is an apocalyptic number.

640537154 is a deficient number, since it is larger than the sum of its proper divisors (320268580).

640537154 is a wasteful number, since it uses less digits than its factorization.

640537154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320268579.

The product of its (nonzero) digits is 50400, while the sum is 35.

The square root of 640537154 is about 25308.8354927681. The cubic root of 640537154 is about 862.0149050956.

The spelling of 640537154 in words is "six hundred forty million, five hundred thirty-seven thousand, one hundred fifty-four".