7251810021 has 12 divisors (see below), whose sum is σ = 10535387148. Its totient is φ = 4806593664.

The previous prime is 7251809989. The next prime is 7251810023. The reversal of 7251810021 is 1200181527.

It can be written as a sum of positive squares in 2 ways, for example, as 5607912996 + 1643897025 = 74886^2 + 40545^2 .

It is not a de Polignac number, because 7251810021 - 2⁵ = 7251809989 is a prime.

It is a super-3 number, since 3×7251810021³ (a number of 31 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7251810023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2327220 + ... + 2330333.

It is an arithmetic number, because the mean of its divisors is an integer number (877948929).

Almost surely, 2^7251810021 is an apocalyptic number.

It is an amenable number.

7251810021 is a deficient number, since it is larger than the sum of its proper divisors (3283577127).

7251810021 is a wasteful number, since it uses less digits than its factorization.

7251810021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4657732 (or 4657729 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 7251810021 is about 85157.5599756123. The cubic root of 7251810021 is about 1935.5993728432.

Adding to 7251810021 its reverse (1200181527), we get a palindrome (8451991548).

The spelling of 7251810021 in words is "seven billion, two hundred fifty-one million, eight hundred ten thousand, twenty-one".