144749781 has 32 divisors (see below), whose sum is σ = 247708800. Its totient is φ = 82563840.

The previous prime is 144749749. The next prime is 144749783. The reversal of 144749781 is 187947441.

It is a happy number.

144749781 is a `hidden beast` number, since 14 + 474 + 97 + 81 = 666.

It is not a de Polignac number, because 144749781 - 2⁵ = 144749749 is a prime.

It is a super-2 number, since 2×144749781² = 41904998199095922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (144749783) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9286 + ... + 19383.

It is an arithmetic number, because the mean of its divisors is an integer number (7740900).

Almost surely, 2^144749781 is an apocalyptic number.

144749781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

144749781 is a deficient number, since it is larger than the sum of its proper divisors (102959019).

144749781 is a wasteful number, since it uses less digits than its factorization.

144749781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28706 (or 28700 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 144749781 is about 12031.2003141831. The cubic root of 144749781 is about 525.0564184266.

It can be divided in two parts, 144749 and 781, that added together give a triangular number (145530 = T₅₃₉).

The spelling of 144749781 in words is "one hundred forty-four million, seven hundred forty-nine thousand, seven hundred eighty-one".