12021121987 has 8 divisors (see below), whose sum is σ = 13752848736. Its totient is φ = 10293001152.

The previous prime is 12021121969. The next prime is 12021121997. The reversal of 12021121987 is 78912112021.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-12021121987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12021121997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 894328 + ... + 907669.

It is an arithmetic number, because the mean of its divisors is an integer number (1719106092).

Almost surely, 2^12021121987 is an apocalyptic number.

12021121987 is a deficient number, since it is larger than the sum of its proper divisors (1731726749).

12021121987 is an equidigital number, since it uses as much as digits as its factorization.

12021121987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1802957.

The product of its (nonzero) digits is 4032, while the sum is 34.

The spelling of 12021121987 in words is "twelve billion, twenty-one million, one hundred twenty-one thousand, nine hundred eighty-seven".