1242621881 has 4 divisors (see below), whose sum is σ = 1242856692. Its totient is φ = 1242387072.

The previous prime is 1242621847. The next prime is 1242621901. The reversal of 1242621881 is 1881262421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1881262421 = 17417 ⋅108013.

It can be written as a sum of positive squares in 2 ways, for example, as 353628025 + 888993856 = 18805^2 + 29816^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1242621881 is a prime.

It is a super-2 number, since 2×1242621881² = 3088218278279956322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1242624881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109280 + ... + 120113.

It is an arithmetic number, because the mean of its divisors is an integer number (310714173).

Almost surely, 2^1242621881 is an apocalyptic number.

It is an amenable number.

1242621881 is a deficient number, since it is larger than the sum of its proper divisors (234811).

1242621881 is an equidigital number, since it uses as much as digits as its factorization.

1242621881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234810.

The product of its digits is 12288, while the sum is 35.

The square root of 1242621881 is about 35250.8422736252. The cubic root of 1242621881 is about 1075.0937379230.

The spelling of 1242621881 in words is "one billion, two hundred forty-two million, six hundred twenty-one thousand, eight hundred eighty-one".