2051999401 has 9 divisors (see below), whose sum is σ = 2077821399. Its totient is φ = 2026496064.

The previous prime is 2051999387. The next prime is 2051999407. The reversal of 2051999401 is 1049991502.

The square root of 2051999401 is 45299.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 921426025 + 1130573376 = 30355^2 + 33624^2 .

It is not a de Polignac number, because 2051999401 - 2²⁷ = 1917781673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2051999407) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4393770 + ... + 4394236.

Almost surely, 2^2051999401 is an apocalyptic number.

2051999401 is the 45299-th square number.

2051999401 is the 22650-th centered octagonal number.

It is an amenable number.

2051999401 is a deficient number, since it is larger than the sum of its proper divisors (25821998).

2051999401 is an frugal number, since it uses more digits than its factorization.

2051999401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 40.

The cubic root of 2051999401 is about 1270.7469516284.

The spelling of 2051999401 in words is "two billion, fifty-one million, nine hundred ninety-nine thousand, four hundred one".