1220636887851 has 32 divisors (see below), whose sum is σ = 1831261985280. Its totient is φ = 719424288000.

The previous prime is 1220636887819. The next prime is 1220636887859. The reversal of 1220636887851 is 1587886360221.

It is not a de Polignac number, because 1220636887851 - 2⁵ = 1220636887819 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a junction number, because it is equal to n+sod(n) for n = 1220636887791 and 1220636887800.

It is not an unprimeable number, because it can be changed into a prime (1220636887859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11300800 + ... + 11408301.

It is an arithmetic number, because the mean of its divisors is an integer number (57226937040).

Almost surely, 2^{1220636887851} is an apocalyptic number.

1220636887851 is a deficient number, since it is larger than the sum of its proper divisors (610625097429).

1220636887851 is a wasteful number, since it uses less digits than its factorization.

1220636887851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22709187.

The product of its (nonzero) digits is 7741440, while the sum is 57.

The spelling of 1220636887851 in words is "one trillion, two hundred twenty billion, six hundred thirty-six million, eight hundred eighty-seven thousand, eight hundred fifty-one".