121681399 has 8 divisors (see below), whose sum is σ = 142456608. Its totient is φ = 101754240.

The previous prime is 121681381. The next prime is 121681429. The reversal of 121681399 is 993186121.

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

It is not a de Polignac number, because 121681399 - 2⁹ = 121680887 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121681309) 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, 211702 + ... + 212275.

It is an arithmetic number, because the mean of its divisors is an integer number (17807076).

Almost surely, 2^121681399 is an apocalyptic number.

121681399 is a deficient number, since it is larger than the sum of its proper divisors (20775209).

121681399 is an equidigital number, since it uses as much as digits as its factorization.

121681399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424025.

The product of its digits is 23328, while the sum is 40.

The square root of 121681399 is about 11030.9291993014. The cubic root of 121681399 is about 495.5354529569.

The spelling of 121681399 in words is "one hundred twenty-one million, six hundred eighty-one thousand, three hundred ninety-nine".