1242991872 has 144 divisors (see below), whose sum is σ = 3794972160. Its totient is φ = 400896000.

The previous prime is 1242991861. The next prime is 1242991877. The reversal of 1242991872 is 2781992421.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242991877) 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, 211372 + ... + 217172.

Almost surely, 2^1242991872 is an apocalyptic number.

1242991872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1242991872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1897486080).

1242991872 is an abundant number, since it is smaller than the sum of its proper divisors (2551980288).

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

1242991872 is an equidigital number, since it uses as much as digits as its factorization.

1242991872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5857 (or 5837 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 1242991872 is about 35256.0898569311. The cubic root of 1242991872 is about 1075.2004304845.

The spelling of 1242991872 in words is "one billion, two hundred forty-two million, nine hundred ninety-one thousand, eight hundred seventy-two".