139920581 has 4 divisors (see below), whose sum is σ = 143174592. Its totient is φ = 136666572.

The previous prime is 139920553. The next prime is 139920587. The reversal of 139920581 is 185029931.

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 a de Polignac number, because none of the positive numbers 2^k-139920581 is a prime.

It is a super-2 number, since 2×139920581² = 39155537974755122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139920587) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1626941 + ... + 1627026.

It is an arithmetic number, because the mean of its divisors is an integer number (35793648).

Almost surely, 2^139920581 is an apocalyptic number.

It is an amenable number.

139920581 is a deficient number, since it is larger than the sum of its proper divisors (3254011).

139920581 is an equidigital number, since it uses as much as digits as its factorization.

139920581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3254010.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 139920581 is about 11828.8030248204. The cubic root of 139920581 is about 519.1512052584.

The spelling of 139920581 in words is "one hundred thirty-nine million, nine hundred twenty thousand, five hundred eighty-one".