69661021 has 2 divisors, whose sum is σ = 69661022. Its totient is φ = 69661020.

The previous prime is 69661001. The next prime is 69661093. The reversal of 69661021 is 12016696.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48372025 + 21288996 = 6955^2 + 4614^2 .

It is a cyclic number.

It is not a de Polignac number, because 69661021 - 2¹⁵ = 69628253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (69661001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34830510 + 34830511.

It is an arithmetic number, because the mean of its divisors is an integer number (34830511).

Almost surely, 2^69661021 is an apocalyptic number.

It is an amenable number.

69661021 is a deficient number, since it is larger than the sum of its proper divisors (1).

69661021 is an equidigital number, since it uses as much as digits as its factorization.

69661021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 69661021 is about 8346.3178108673. The cubic root of 69661021 is about 411.4622012567.

The spelling of 69661021 in words is "sixty-nine million, six hundred sixty-one thousand, twenty-one".