165451951 has 16 divisors (see below), whose sum is σ = 192374784. Its totient is φ = 139369824.

The previous prime is 165451907. The next prime is 165451997. The reversal of 165451951 is 159154561.

It is a cyclic number.

It is not a de Polignac number, because 165451951 - 2¹⁵ = 165419183 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165451951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165451051) 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, 128925 + ... + 130201.

It is an arithmetic number, because the mean of its divisors is an integer number (12023424).

Almost surely, 2^165451951 is an apocalyptic number.

165451951 is a deficient number, since it is larger than the sum of its proper divisors (26922833).

165451951 is a wasteful number, since it uses less digits than its factorization.

165451951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1590.

The product of its digits is 27000, while the sum is 37.

The square root of 165451951 is about 12862.8127172870. The cubic root of 165451951 is about 548.9809792758.

It can be divided in two parts, 16545 and 1951, that added together give a square (18496 = 136²).

The spelling of 165451951 in words is "one hundred sixty-five million, four hundred fifty-one thousand, nine hundred fifty-one".