1221880087 has 4 divisors (see below), whose sum is σ = 1222102336. Its totient is φ = 1221657840.

The previous prime is 1221880067. The next prime is 1221880133. The reversal of 1221880087 is 7800881221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221880087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221880007) 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, 102663 + ... + 113944.

It is an arithmetic number, because the mean of its divisors is an integer number (305525584).

Almost surely, 2^1221880087 is an apocalyptic number.

1221880087 is a deficient number, since it is larger than the sum of its proper divisors (222249).

1221880087 is an equidigital number, since it uses as much as digits as its factorization.

1221880087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222248.

The product of its (nonzero) digits is 14336, while the sum is 37.

The square root of 1221880087 is about 34955.4013994976. The cubic root of 1221880087 is about 1069.0783360999.

The spelling of 1221880087 in words is "one billion, two hundred twenty-one million, eight hundred eighty thousand, eighty-seven".