99720637 has 2 divisors, whose sum is σ = 99720638. Its totient is φ = 99720636.

The previous prime is 99720631. The next prime is 99720653. The reversal of 99720637 is 73602799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99720196 + 441 = 9986^2 + 21^2 .

It is a cyclic number.

It is not a de Polignac number, because 99720637 - 2¹⁵ = 99687869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 99720593 and 99720602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99720631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49860318 + 49860319.

It is an arithmetic number, because the mean of its divisors is an integer number (49860319).

Almost surely, 2^99720637 is an apocalyptic number.

It is an amenable number.

99720637 is a deficient number, since it is larger than the sum of its proper divisors (1).

99720637 is an equidigital number, since it uses as much as digits as its factorization.

99720637 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 142884, while the sum is 43.

The square root of 99720637 is about 9986.0220808889. The cubic root of 99720637 is about 463.7262508453.

The spelling of 99720637 in words is "ninety-nine million, seven hundred twenty thousand, six hundred thirty-seven".