647198551 has 8 divisors (see below), whose sum is σ = 687464064. Its totient is φ = 607176960.

The previous prime is 647198527. The next prime is 647198569. The reversal of 647198551 is 155891746.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 647198551 - 2¹¹ = 647196503 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 (647198521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55495 + ... + 66136.

It is an arithmetic number, because the mean of its divisors is an integer number (85933008).

Almost surely, 2^647198551 is an apocalyptic number.

647198551 is a deficient number, since it is larger than the sum of its proper divisors (40265513).

647198551 is a wasteful number, since it uses less digits than its factorization.

647198551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121961.

The product of its digits is 302400, while the sum is 46.

The square root of 647198551 is about 25440.0973072038. The cubic root of 647198551 is about 864.9928389931.

The spelling of 647198551 in words is "six hundred forty-seven million, one hundred ninety-eight thousand, five hundred fifty-one".