51217149 has 4 divisors (see below), whose sum is σ = 68289536. Its totient is φ = 34144764.

The previous prime is 51217109. The next prime is 51217151. The reversal of 51217149 is 94171215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51217149 - 2¹⁵ = 51184381 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 (51217109) 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, 8536189 + ... + 8536194.

It is an arithmetic number, because the mean of its divisors is an integer number (17072384).

Almost surely, 2^51217149 is an apocalyptic number.

It is an amenable number.

51217149 is a deficient number, since it is larger than the sum of its proper divisors (17072387).

51217149 is a wasteful number, since it uses less digits than its factorization.

51217149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17072386.

The product of its digits is 2520, while the sum is 30.

The square root of 51217149 is about 7156.6157504787. The cubic root of 51217149 is about 371.3685596690.

The spelling of 51217149 in words is "fifty-one million, two hundred seventeen thousand, one hundred forty-nine".