121401840 has 160 divisors (see below), whose sum is σ = 434257920. Its totient is φ = 27482112.

The previous prime is 121401829. The next prime is 121401851. The reversal of 121401840 is 48104121.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (121401829) and next prime (121401851).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 213076 + ... + 213644.

It is an arithmetic number, because the mean of its divisors is an integer number (2714112).

Almost surely, 2^121401840 is an apocalyptic number.

121401840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121401840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (217128960).

121401840 is an abundant number, since it is smaller than the sum of its proper divisors (312856080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121401840 is a wasteful number, since it uses less digits than its factorization.

121401840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 121401840 is about 11018.2503148186. The cubic root of 121401840 is about 495.1556698433.

Adding to 121401840 its reverse (48104121), we get a palindrome (169505961).

The spelling of 121401840 in words is "one hundred twenty-one million, four hundred one thousand, eight hundred forty".