18961272 has 96 divisors (see below), whose sum is σ = 56862000. Its totient is φ = 5660160.

The previous prime is 18961253. The next prime is 18961289. The reversal of 18961272 is 27216981.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70354 + ... + 70622.

Almost surely, 2^18961272 is an apocalyptic number.

18961272 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18961272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28431000).

18961272 is an abundant number, since it is smaller than the sum of its proper divisors (37900728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18961272 is a wasteful number, since it uses less digits than its factorization.

18961272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381 (or 374 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 18961272 is about 4354.4542712032. The cubic root of 18961272 is about 266.6587400422.

It can be divided in two parts, 1896127 and 2, that added together give a square (1896129 = 1377²).

The spelling of 18961272 in words is "eighteen million, nine hundred sixty-one thousand, two hundred seventy-two".