690621605 has 8 divisors (see below), whose sum is σ = 829880952. Its totient is φ = 551740608.

The previous prime is 690621601. The next prime is 690621623. The reversal of 690621605 is 506126096.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 496799521 + 193822084 = 22289^2 + 13922^2 .

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 690621605 - 2² = 690621601 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 (690621601) 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, 90554 + ... + 97883.

It is an arithmetic number, because the mean of its divisors is an integer number (103735119).

Almost surely, 2^690621605 is an apocalyptic number.

It is an amenable number.

690621605 is a deficient number, since it is larger than the sum of its proper divisors (139259347).

690621605 is a wasteful number, since it uses less digits than its factorization.

690621605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189175.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 690621605 is about 26279.6804584835. The cubic root of 690621605 is about 883.9208675403.

The spelling of 690621605 in words is "six hundred ninety million, six hundred twenty-one thousand, six hundred five".