144705781 has 4 divisors (see below), whose sum is σ = 157860864. Its totient is φ = 131550700.

The previous prime is 144705763. The next prime is 144705797. The reversal of 144705781 is 187507441.

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 144705781 - 2⁵ = 144705749 is a prime.

It is a super-2 number, since 2×144705781² = 41879526109639922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 144705781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (144709781) 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, 6577525 + ... + 6577546.

It is an arithmetic number, because the mean of its divisors is an integer number (39465216).

Almost surely, 2^144705781 is an apocalyptic number.

144705781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

144705781 is a deficient number, since it is larger than the sum of its proper divisors (13155083).

144705781 is a wasteful number, since it uses less digits than its factorization.

144705781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13155082.

The product of its (nonzero) digits is 31360, while the sum is 37.

The square root of 144705781 is about 12029.3715962223. The cubic root of 144705781 is about 525.0032120741.

The spelling of 144705781 in words is "one hundred forty-four million, seven hundred five thousand, seven hundred eighty-one".