690138391 has 16 divisors (see below), whose sum is σ = 740275200. Its totient is φ = 641935008.

The previous prime is 690138377. The next prime is 690138439. The reversal of 690138391 is 193831096.

It is a cyclic number.

It is not a de Polignac number, because 690138391 - 2⁵ = 690138359 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 (690138301) 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, 118905 + ... + 124573.

It is an arithmetic number, because the mean of its divisors is an integer number (46267200).

Almost surely, 2^690138391 is an apocalyptic number.

690138391 is a deficient number, since it is larger than the sum of its proper divisors (50136809).

690138391 is a wasteful number, since it uses less digits than its factorization.

690138391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5838.

The product of its (nonzero) digits is 34992, while the sum is 40.

The square root of 690138391 is about 26270.4851687212. The cubic root of 690138391 is about 883.7146655767.

The spelling of 690138391 in words is "six hundred ninety million, one hundred thirty-eight thousand, three hundred ninety-one".