1242221887 has 4 divisors (see below), whose sum is σ = 1242376096. Its totient is φ = 1242067680.

The previous prime is 1242221839. The next prime is 1242221899. The reversal of 1242221887 is 7881222421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7881222421 = 83 ⋅94954487.

It is a cyclic number.

It is not a de Polignac number, because 1242221887 - 2¹⁵ = 1242189119 is a prime.

It is a super-3 number, since 3×1242221887³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242221087) 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, 64314 + ... + 81367.

It is an arithmetic number, because the mean of its divisors is an integer number (310594024).

Almost surely, 2^1242221887 is an apocalyptic number.

1242221887 is a deficient number, since it is larger than the sum of its proper divisors (154209).

1242221887 is an equidigital number, since it uses as much as digits as its factorization.

1242221887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154208.

The product of its digits is 28672, while the sum is 37.

The square root of 1242221887 is about 35245.1682787868. The cubic root of 1242221887 is about 1074.9783697108.

The spelling of 1242221887 in words is "one billion, two hundred forty-two million, two hundred twenty-one thousand, eight hundred eighty-seven".