499999997621 has 2 divisors, whose sum is σ = 499999997622. Its totient is φ = 499999997620.

The previous prime is 499999997597. The next prime is 499999997657. The reversal of 499999997621 is 126799999994.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 488845680625 + 11154316996 = 699175^2 + 105614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-499999997621 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 499999997621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (499999997221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249999998810 + 249999998811.

It is an arithmetic number, because the mean of its divisors is an integer number (249999998811).

Almost surely, 2^499999997621 is an apocalyptic number.

It is an amenable number.

499999997621 is a deficient number, since it is larger than the sum of its proper divisors (1).

499999997621 is an equidigital number, since it uses as much as digits as its factorization.

499999997621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1607077584, while the sum is 83.

The spelling of 499999997621 in words is "four hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-seven thousand, six hundred twenty-one".