2021161651 has 8 divisors (see below), whose sum is σ = 2128377600. Its totient is φ = 1914029640.

The previous prime is 2021161619. The next prime is 2021161661. The reversal of 2021161651 is 1561611202.

It is a happy number.

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 2021161651 - 2⁵ = 2021161619 is a prime.

It is a super-3 number, since 3×2021161651³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2021161661) 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, 31890 + ... + 71128.

It is an arithmetic number, because the mean of its divisors is an integer number (266047200).

Almost surely, 2^2021161651 is an apocalyptic number.

2021161651 is a deficient number, since it is larger than the sum of its proper divisors (107215949).

2021161651 is a wasteful number, since it uses less digits than its factorization.

2021161651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41969.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 2021161651 is about 44957.3314488305. The cubic root of 2021161651 is about 1264.3491370751.

Adding to 2021161651 its reverse (1561611202), we get a palindrome (3582772853).

The spelling of 2021161651 in words is "two billion, twenty-one million, one hundred sixty-one thousand, six hundred fifty-one".