691990645207 has 8 divisors (see below), whose sum is σ = 732722560416. Its totient is φ = 651261683712.

The previous prime is 691990645189. The next prime is 691990645217. The reversal of 691990645207 is 702546099196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 691990645207 - 2¹⁹ = 691990120919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691990645217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 246723 + ... + 1202020.

It is an arithmetic number, because the mean of its divisors is an integer number (91590320052).

Almost surely, 2^691990645207 is an apocalyptic number.

691990645207 is a deficient number, since it is larger than the sum of its proper divisors (40731915209).

691990645207 is a wasteful number, since it uses less digits than its factorization.

691990645207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1476857.

The product of its (nonzero) digits is 7348320, while the sum is 58.

The spelling of 691990645207 in words is "six hundred ninety-one billion, nine hundred ninety million, six hundred forty-five thousand, two hundred seven".