51167661 has 4 divisors (see below), whose sum is σ = 68223552. Its totient is φ = 34111772.

The previous prime is 51167659. The next prime is 51167681. The reversal of 51167661 is 16676115.

Added to its reverse (16676115) it gives a triangular number (67843776 = T₁₁₆₄₈).

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 a cyclic number.

It is not a de Polignac number, because 51167661 - 2¹ = 51167659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51167681) 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, 8527941 + ... + 8527946.

It is an arithmetic number, because the mean of its divisors is an integer number (17055888).

Almost surely, 2^51167661 is an apocalyptic number.

It is an amenable number.

51167661 is a deficient number, since it is larger than the sum of its proper divisors (17055891).

51167661 is a wasteful number, since it uses less digits than its factorization.

51167661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17055890.

The product of its digits is 7560, while the sum is 33.

The square root of 51167661 is about 7153.1574147365. The cubic root of 51167661 is about 371.2489108789.

Adding to 51167661 its reverse (16676115), we get a triangular number (67843776 = T₁₁₆₄₈).

The spelling of 51167661 in words is "fifty-one million, one hundred sixty-seven thousand, six hundred sixty-one".