690933721 has 8 divisors (see below), whose sum is σ = 697539584. Its totient is φ = 684346320.

The previous prime is 690933713. The next prime is 690933739. The reversal of 690933721 is 127339096.

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 690933721 - 2³ = 690933713 is a prime.

It is a super-3 number, since 3×690933721³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690933781) 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, 77431 + ... + 85891.

It is an arithmetic number, because the mean of its divisors is an integer number (87192448).

Almost surely, 2^690933721 is an apocalyptic number.

It is an amenable number.

690933721 is a deficient number, since it is larger than the sum of its proper divisors (6605863).

690933721 is a wasteful number, since it uses less digits than its factorization.

690933721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9231.

The product of its (nonzero) digits is 61236, while the sum is 40.

The square root of 690933721 is about 26285.6181399639. The cubic root of 690933721 is about 884.0540057128.

The spelling of 690933721 in words is "six hundred ninety million, nine hundred thirty-three thousand, seven hundred twenty-one".