690985501 has 2 divisors, whose sum is σ = 690985502. Its totient is φ = 690985500.

The previous prime is 690985487. The next prime is 690985531. The reversal of 690985501 is 105589096.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 670292100 + 20693401 = 25890^2 + 4549^2 .

It is a cyclic number.

It is not a de Polignac number, because 690985501 - 2²⁵ = 657431069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690985531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345492750 + 345492751.

It is an arithmetic number, because the mean of its divisors is an integer number (345492751).

Almost surely, 2^690985501 is an apocalyptic number.

It is an amenable number.

690985501 is a deficient number, since it is larger than the sum of its proper divisors (1).

690985501 is an equidigital number, since it uses as much as digits as its factorization.

690985501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 43.

The square root of 690985501 is about 26286.6030707659. The cubic root of 690985501 is about 884.0760894388.

The spelling of 690985501 in words is "six hundred ninety million, nine hundred eighty-five thousand, five hundred one".