1998770651 has 8 divisors (see below), whose sum is σ = 2020544400. Its totient is φ = 1977020928.

The previous prime is 1998770647. The next prime is 1998770681. The reversal of 1998770651 is 1560778991.

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

It is a cyclic number.

It is not a de Polignac number, because 1998770651 - 2² = 1998770647 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1998770593 and 1998770602.

It is not an unprimeable number, because it can be changed into a prime (1998770681) 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, 198695 + ... + 208511.

It is an arithmetic number, because the mean of its divisors is an integer number (252568050).

Almost surely, 2^1998770651 is an apocalyptic number.

1998770651 is a deficient number, since it is larger than the sum of its proper divisors (21773749).

1998770651 is an equidigital number, since it uses as much as digits as its factorization.

1998770651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12013.

The product of its (nonzero) digits is 952560, while the sum is 53.

The square root of 1998770651 is about 44707.6128975815. The cubic root of 1998770651 is about 1259.6628498709.

The spelling of 1998770651 in words is "one billion, nine hundred ninety-eight million, seven hundred seventy thousand, six hundred fifty-one".