151391981 has 8 divisors (see below), whose sum is σ = 171618720. Its totient is φ = 132391152.

The previous prime is 151391969. The next prime is 151392011. The reversal of 151391981 is 189193151.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 151391981 - 2¹⁴ = 151375597 is a prime.

It is a super-2 number, since 2×151391981² = 45839063822208722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151391381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 306215 + ... + 306708.

It is an arithmetic number, because the mean of its divisors is an integer number (21452340).

Almost surely, 2^151391981 is an apocalyptic number.

It is an amenable number.

151391981 is a deficient number, since it is larger than the sum of its proper divisors (20226739).

151391981 is a wasteful number, since it uses less digits than its factorization.

151391981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612955.

The product of its digits is 9720, while the sum is 38.

The square root of 151391981 is about 12304.1448707336. The cubic root of 151391981 is about 532.9677827962.

The spelling of 151391981 in words is "one hundred fifty-one million, three hundred ninety-one thousand, nine hundred eighty-one".