654738991 has 4 divisors (see below), whose sum is σ = 655090432. Its totient is φ = 654387552.

The previous prime is 654738983. The next prime is 654739049. The reversal of 654738991 is 199837456.

It is a happy number.

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 654738991 - 2³ = 654738983 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 (654738691) 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, 172911 + ... + 176656.

It is an arithmetic number, because the mean of its divisors is an integer number (163772608).

Almost surely, 2^654738991 is an apocalyptic number.

654738991 is a deficient number, since it is larger than the sum of its proper divisors (351441).

654738991 is a wasteful number, since it uses less digits than its factorization.

654738991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351440.

The product of its digits is 1632960, while the sum is 52.

The square root of 654738991 is about 25587.8680432739. The cubic root of 654738991 is about 868.3391889883.

The spelling of 654738991 in words is "six hundred fifty-four million, seven hundred thirty-eight thousand, nine hundred ninety-one".