690726561 has 16 divisors (see below), whose sum is σ = 1054272384. Its totient is φ = 394049664.

The previous prime is 690726559. The next prime is 690726571. The reversal of 690726561 is 165627096.

It is not a de Polignac number, because 690726561 - 2¹ = 690726559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (690726521) 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, 13956 + ... + 39701.

It is an arithmetic number, because the mean of its divisors is an integer number (65892024).

Almost surely, 2^690726561 is an apocalyptic number.

It is an amenable number.

690726561 is a deficient number, since it is larger than the sum of its proper divisors (363545823).

690726561 is a wasteful number, since it uses less digits than its factorization.

690726561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54280.

The product of its (nonzero) digits is 136080, while the sum is 42.

The square root of 690726561 is about 26281.6772866573. The cubic root of 690726561 is about 883.9656427103.

The spelling of 690726561 in words is "six hundred ninety million, seven hundred twenty-six thousand, five hundred sixty-one".