39699661 has 2 divisors, whose sum is σ = 39699662. Its totient is φ = 39699660.

The previous prime is 39699659. The next prime is 39699691. The reversal of 39699661 is 16699693.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38365636 + 1334025 = 6194^2 + 1155^2 .

It is a cyclic number.

It is not a de Polignac number, because 39699661 - 2¹ = 39699659 is a prime.

Together with 39699659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39699601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19849830 + 19849831.

It is an arithmetic number, because the mean of its divisors is an integer number (19849831).

Almost surely, 2^39699661 is an apocalyptic number.

It is an amenable number.

39699661 is a deficient number, since it is larger than the sum of its proper divisors (1).

39699661 is an equidigital number, since it uses as much as digits as its factorization.

39699661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 472392, while the sum is 49.

The square root of 39699661 is about 6300.7666993787. The cubic root of 39699661 is about 341.1370839409.

The spelling of 39699661 in words is "thirty-nine million, six hundred ninety-nine thousand, six hundred sixty-one".