998150821 has 2 divisors, whose sum is σ = 998150822. Its totient is φ = 998150820.

The previous prime is 998150771. The next prime is 998150843. The reversal of 998150821 is 128051899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 521208900 + 476941921 = 22830^2 + 21839^2 .

It is an emirp because it is prime and its reverse (128051899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998150821 - 2¹⁵ = 998118053 is a prime.

It is a super-2 number, since 2×998150821² = 1992610122925948082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998150861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499075410 + 499075411.

It is an arithmetic number, because the mean of its divisors is an integer number (499075411).

Almost surely, 2^998150821 is an apocalyptic number.

It is an amenable number.

998150821 is a deficient number, since it is larger than the sum of its proper divisors (1).

998150821 is an equidigital number, since it uses as much as digits as its factorization.

998150821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 43.

The square root of 998150821 is about 31593.5249853510. The cubic root of 998150821 is about 999.3832266689.

The spelling of 998150821 in words is "nine hundred ninety-eight million, one hundred fifty thousand, eight hundred twenty-one".