15401981 has 8 divisors (see below), whose sum is σ = 17721600. Its totient is φ = 13112208.

The previous prime is 15401977. The next prime is 15401993. The reversal of 15401981 is 18910451.

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 15401981 - 2² = 15401977 is a prime.

It is a super-2 number, since 2×15401981² = 474442037448722, 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 (15401921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6341 + ... + 8426.

It is an arithmetic number, because the mean of its divisors is an integer number (2215200).

Almost surely, 2^15401981 is an apocalyptic number.

It is an amenable number.

15401981 is a deficient number, since it is larger than the sum of its proper divisors (2319619).

15401981 is a wasteful number, since it uses less digits than its factorization.

15401981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14923.

The product of its (nonzero) digits is 1440, while the sum is 29.

The square root of 15401981 is about 3924.5357687248. The cubic root of 15401981 is about 248.8048610090.

The spelling of 15401981 in words is "fifteen million, four hundred one thousand, nine hundred eighty-one".