698991640 has 64 divisors (see below), whose sum is σ = 1631275200. Its totient is φ = 269240832.

The previous prime is 698991593. The next prime is 698991647. The reversal of 698991640 is 46199896.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (698991647) 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, 710589 + ... + 711571.

It is an arithmetic number, because the mean of its divisors is an integer number (25488675).

Almost surely, 2^698991640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 698991640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (815637600).

698991640 is an abundant number, since it is smaller than the sum of its proper divisors (932283560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

698991640 is a wasteful number, since it uses less digits than its factorization.

698991640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1636 (or 1632 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 52.

The square root of 698991640 is about 26438.4500302117. The cubic root of 698991640 is about 887.4774507264.

The spelling of 698991640 in words is "six hundred ninety-eight million, nine hundred ninety-one thousand, six hundred forty".