1990010101 has 4 divisors (see below), whose sum is σ = 1993225600. Its totient is φ = 1986794604.

The previous prime is 1990010059. The next prime is 1990010147. The reversal of 1990010101 is 1010100991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1990010101 - 2²³ = 1981621493 is a prime.

It is a Duffinian number.

1990010101 is a modest number, since divided by 10101 gives 1990 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990010501) 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, 1606821 + ... + 1608058.

It is an arithmetic number, because the mean of its divisors is an integer number (498306400).

Almost surely, 2^1990010101 is an apocalyptic number.

It is an amenable number.

1990010101 is a deficient number, since it is larger than the sum of its proper divisors (3215499).

1990010101 is an equidigital number, since it uses as much as digits as its factorization.

1990010101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3215498.

The product of its (nonzero) digits is 81, while the sum is 22.

The square root of 1990010101 is about 44609.5292622552. The cubic root of 1990010101 is about 1257.8198001169.

The spelling of 1990010101 in words is "one billion, nine hundred ninety million, ten thousand, one hundred one".