149747981 has 2 divisors, whose sum is σ = 149747982. Its totient is φ = 149747980.

The previous prime is 149747977. The next prime is 149748023. The reversal of 149747981 is 189747941.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141395881 + 8352100 = 11891^2 + 2890^2 .

It is an emirp because it is prime and its reverse (189747941) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 149747981 - 2² = 149747977 is a prime.

It is a super-2 number, since 2×149747981² = 44848915627152722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (149749981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74873990 + 74873991.

It is an arithmetic number, because the mean of its divisors is an integer number (74873991).

Almost surely, 2^149747981 is an apocalyptic number.

It is an amenable number.

149747981 is a deficient number, since it is larger than the sum of its proper divisors (1).

149747981 is an equidigital number, since it uses as much as digits as its factorization.

149747981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 50.

The square root of 149747981 is about 12237.1557561388. The cubic root of 149747981 is about 531.0315509523.

The spelling of 149747981 in words is "one hundred forty-nine million, seven hundred forty-seven thousand, nine hundred eighty-one".