1012001989 has 4 divisors (see below), whose sum is σ = 1012949740. Its totient is φ = 1011054240.

The previous prime is 1012001983. The next prime is 1012002011. The reversal of 1012001989 is 9891002101.

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

It can be written as a sum of positive squares in 2 ways, for example, as 354079489 + 657922500 = 18817^2 + 25650^2 .

It is a cyclic number.

It is not a de Polignac number, because 1012001989 - 2⁵ = 1012001957 is a prime.

It is a super-2 number, since 2×1012001989² = 2048296051479912242, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1012001989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1012001983) 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, 472272 + ... + 474409.

It is an arithmetic number, because the mean of its divisors is an integer number (253237435).

Almost surely, 2^1012001989 is an apocalyptic number.

It is an amenable number.

1012001989 is a deficient number, since it is larger than the sum of its proper divisors (947751).

1012001989 is an equidigital number, since it uses as much as digits as its factorization.

1012001989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947750.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 1012001989 is about 31811.9787029980. The cubic root of 1012001989 is about 1003.9847635688.

The spelling of 1012001989 in words is "one billion, twelve million, one thousand, nine hundred eighty-nine".