139749101581 has 2 divisors, whose sum is σ = 139749101582. Its totient is φ = 139749101580.

The previous prime is 139749101519. The next prime is 139749101623. The reversal of 139749101581 is 185101947931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100660252900 + 39088848681 = 317270^2 + 197709^2 .

It is a cyclic number.

It is not a de Polignac number, because 139749101581 - 2¹⁵ = 139749068813 is a prime.

It is a super-2 number, since 2×139749101581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139749101381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69874550790 + 69874550791.

It is an arithmetic number, because the mean of its divisors is an integer number (69874550791).

Almost surely, 2^139749101581 is an apocalyptic number.

It is an amenable number.

139749101581 is a deficient number, since it is larger than the sum of its proper divisors (1).

139749101581 is an equidigital number, since it uses as much as digits as its factorization.

139749101581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 49.

The spelling of 139749101581 in words is "one hundred thirty-nine billion, seven hundred forty-nine million, one hundred one thousand, five hundred eighty-one".