1988621197 has 2 divisors, whose sum is σ = 1988621198. Its totient is φ = 1988621196.

The previous prime is 1988621191. The next prime is 1988621207. The reversal of 1988621197 is 7911268891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1982564676 + 6056521 = 44526^2 + 2461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1988621197 is a prime.

It is a super-2 number, since 2×1988621197² = 7909228530315425618, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1988621191) 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 as a sum of consecutive naturals, namely, 994310598 + 994310599.

It is an arithmetic number, because the mean of its divisors is an integer number (994310599).

Almost surely, 2^1988621197 is an apocalyptic number.

It is an amenable number.

1988621197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1988621197 is an equidigital number, since it uses as much as digits as its factorization.

1988621197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 52.

The square root of 1988621197 is about 44593.9591985282. The cubic root of 1988621197 is about 1257.5271051972.

The spelling of 1988621197 in words is "one billion, nine hundred eighty-eight million, six hundred twenty-one thousand, one hundred ninety-seven".