99511021 has 2 divisors, whose sum is σ = 99511022. Its totient is φ = 99511020.

The previous prime is 99511003. The next prime is 99511057. The reversal of 99511021 is 12011599.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57972996 + 41538025 = 7614^2 + 6445^2 .

It is a cyclic number.

It is not a de Polignac number, because 99511021 - 2⁷ = 99510893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99511001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49755510 + 49755511.

It is an arithmetic number, because the mean of its divisors is an integer number (49755511).

Almost surely, 2^99511021 is an apocalyptic number.

It is an amenable number.

99511021 is a deficient number, since it is larger than the sum of its proper divisors (1).

99511021 is an equidigital number, since it uses as much as digits as its factorization.

99511021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 810, while the sum is 28.

The square root of 99511021 is about 9975.5210891462. The cubic root of 99511021 is about 463.4011003939.

The spelling of 99511021 in words is "ninety-nine million, five hundred eleven thousand, twenty-one".