8501388421 has 2 divisors, whose sum is σ = 8501388422. Its totient is φ = 8501388420.

The previous prime is 8501388377. The next prime is 8501388431. The reversal of 8501388421 is 1248831058.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7220750625 + 1280637796 = 84975^2 + 35786^2 .

It is a cyclic number.

It is not a de Polignac number, because 8501388421 - 2²³ = 8492999813 is a prime.

It is a super-3 number, since 3×8501388421³ (a number of 31 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8501388431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4250694210 + 4250694211.

It is an arithmetic number, because the mean of its divisors is an integer number (4250694211).

Almost surely, 2^8501388421 is an apocalyptic number.

It is an amenable number.

8501388421 is a deficient number, since it is larger than the sum of its proper divisors (1).

8501388421 is an equidigital number, since it uses as much as digits as its factorization.

8501388421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61440, while the sum is 40.

The square root of 8501388421 is about 92202.9740355483. The cubic root of 8501388421 is about 2040.9386636474.

The spelling of 8501388421 in words is "eight billion, five hundred one million, three hundred eighty-eight thousand, four hundred twenty-one".