251536542 has 16 divisors (see below), whose sum is σ = 519301632. Its totient is φ = 81140760.

The previous prime is 251536513. The next prime is 251536543. The reversal of 251536542 is 245635152.

It is a super-2 number, since 2×251536542² = 126541263922635528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251536543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 675988 + ... + 676359.

It is an arithmetic number, because the mean of its divisors is an integer number (32456352).

Almost surely, 2^251536542 is an apocalyptic number.

251536542 is an abundant number, since it is smaller than the sum of its proper divisors (267765090).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251536542 is a wasteful number, since it uses less digits than its factorization.

251536542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1352383.

The product of its digits is 36000, while the sum is 33.

The square root of 251536542 is about 15859.9035936540. The cubic root of 251536542 is about 631.2485042346.

The spelling of 251536542 in words is "two hundred fifty-one million, five hundred thirty-six thousand, five hundred forty-two".