1242636540 has 48 divisors (see below), whose sum is σ = 3484591488. Its totient is φ = 330873664.

The previous prime is 1242636529. The next prime is 1242636541. The reversal of 1242636540 is 456362421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242636541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25819 + ... + 56141.

It is an arithmetic number, because the mean of its divisors is an integer number (72595656).

Almost surely, 2^1242636540 is an apocalyptic number.

1242636540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1242636540 is an abundant number, since it is smaller than the sum of its proper divisors (2241954948).

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

1242636540 is a wasteful number, since it uses less digits than its factorization.

1242636540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31018 (or 31016 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 1242636540 is about 35251.0501971218. The cubic root of 1242636540 is about 1075.0979654726.

Adding to 1242636540 its reverse (456362421), we get a palindrome (1698998961).

The spelling of 1242636540 in words is "one billion, two hundred forty-two million, six hundred thirty-six thousand, five hundred forty".