691217128070 has 32 divisors (see below), whose sum is σ = 1422596210688. Its totient is φ = 236878090848.

The previous prime is 691217128061. The next prime is 691217128079. The reversal of 691217128070 is 70821712196.

It is an interprime number because it is at equal distance from previous prime (691217128061) and next prime (691217128079).

It is a super-2 number, since 2×691217128070² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691217128079) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2153894 + ... + 2453913.

It is an arithmetic number, because the mean of its divisors is an integer number (44456131584).

Almost surely, 2^691217128070 is an apocalyptic number.

691217128070 is an abundant number, since it is smaller than the sum of its proper divisors (731379082618).

691217128070 is a wasteful number, since it uses less digits than its factorization.

691217128070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4609964.

The product of its (nonzero) digits is 84672, while the sum is 44.

The spelling of 691217128070 in words is "six hundred ninety-one billion, two hundred seventeen million, one hundred twenty-eight thousand, seventy".