1988621997 has 8 divisors (see below), whose sum is σ = 2652308160. Its totient is φ = 1325341920.

The previous prime is 1988621951. The next prime is 1988622019. The reversal of 1988621997 is 7991268891.

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

It is not a de Polignac number, because 1988621997 - 2¹² = 1988617901 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1988621997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988621197) 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, 89904 + ... + 109817.

It is an arithmetic number, because the mean of its divisors is an integer number (331538520).

Almost surely, 2^1988621997 is an apocalyptic number.

It is an amenable number.

1988621997 is a deficient number, since it is larger than the sum of its proper divisors (663686163).

1988621997 is a wasteful number, since it uses less digits than its factorization.

1988621997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203043.

The product of its digits is 3919104, while the sum is 60.

The square root of 1988621997 is about 44593.9681683521. The cubic root of 1988621997 is about 1257.5272738269.

The spelling of 1988621997 in words is "one billion, nine hundred eighty-eight million, six hundred twenty-one thousand, nine hundred ninety-seven".