2105021551 has 4 divisors (see below), whose sum is σ = 2172925504. Its totient is φ = 2037117600.

The previous prime is 2105021537. The next prime is 2105021587. The reversal of 2105021551 is 1551205012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2105021551 - 2⁵ = 2105021519 is a prime.

It is a super-2 number, since 2×2105021551² = 8862231460348891202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105021251) 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, 33951930 + ... + 33951991.

It is an arithmetic number, because the mean of its divisors is an integer number (543231376).

Almost surely, 2^2105021551 is an apocalyptic number.

2105021551 is a deficient number, since it is larger than the sum of its proper divisors (67903953).

2105021551 is an equidigital number, since it uses as much as digits as its factorization.

2105021551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67903952.

The product of its (nonzero) digits is 500, while the sum is 22.

The square root of 2105021551 is about 45880.5138484738. The cubic root of 2105021551 is about 1281.5990657527.

Adding to 2105021551 its reverse (1551205012), we get a palindrome (3656226563).

The spelling of 2105021551 in words is "two billion, one hundred five million, twenty-one thousand, five hundred fifty-one".