690655680 has 672 divisors, whose sum is σ = 2945099520. Its totient is φ = 150958080.

The previous prime is 690655673. The next prime is 690655687. The reversal of 690655680 is 86556096.

690655680 is a `hidden beast` number, since 6 + 90 + 6 + 556 + 8 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (690655673) and next prime (690655687).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690655687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16061739 + ... + 16061781.

Almost surely, 2^690655680 is an apocalyptic number.

690655680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 690655680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1472549760).

690655680 is an abundant number, since it is smaller than the sum of its proper divisors (2254443840).

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

690655680 is a wasteful number, since it uses less digits than its factorization.

690655680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 690655680 is about 26280.3287650668. The cubic root of 690655680 is about 883.9354047379.

The spelling of 690655680 in words is "six hundred ninety million, six hundred fifty-five thousand, six hundred eighty".