149998781 has 2 divisors, whose sum is σ = 149998782. Its totient is φ = 149998780.

The previous prime is 149998727. The next prime is 149998813. The reversal of 149998781 is 187899941.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 141967225 + 8031556 = 11915^2 + 2834^2 .

It is an emirp because it is prime and its reverse (187899941) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 149998781 - 2¹⁸ = 149736637 is a prime.

It is a super-2 number, since 2×149998781² = 44999268602971922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (149991781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74999390 + 74999391.

It is an arithmetic number, because the mean of its divisors is an integer number (74999391).

Almost surely, 2^149998781 is an apocalyptic number.

It is an amenable number.

149998781 is a deficient number, since it is larger than the sum of its proper divisors (1).

149998781 is an equidigital number, since it uses as much as digits as its factorization.

149998781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1306368, while the sum is 56.

The square root of 149998781 is about 12247.3989483482. The cubic root of 149998781 is about 531.3278452754.

The spelling of 149998781 in words is "one hundred forty-nine million, nine hundred ninety-eight thousand, seven hundred eighty-one".