690400087 has 4 divisors (see below), whose sum is σ = 743507800. Its totient is φ = 637292376.

The previous prime is 690400079. The next prime is 690400091. The reversal of 690400087 is 780004096.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 690400087 - 2³ = 690400079 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 (690400027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26553837 + ... + 26553862.

It is an arithmetic number, because the mean of its divisors is an integer number (185876950).

Almost surely, 2^690400087 is an apocalyptic number.

690400087 is a deficient number, since it is larger than the sum of its proper divisors (53107713).

690400087 is a wasteful number, since it uses less digits than its factorization.

690400087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53107712.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 690400087 is about 26275.4654954008. The cubic root of 690400087 is about 883.8263510835.

The spelling of 690400087 in words is "six hundred ninety million, four hundred thousand, eighty-seven".