121641720 has 32 divisors (see below), whose sum is σ = 364925520. Its totient is φ = 32437760.

The previous prime is 121641719. The next prime is 121641721. The reversal of 121641720 is 27146121.

It is an interprime number because it is at equal distance from previous prime (121641719) and next prime (121641721).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121641721) 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, 506721 + ... + 506960.

Almost surely, 2^121641720 is an apocalyptic number.

121641720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121641720 is an abundant number, since it is smaller than the sum of its proper divisors (243283800).

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

121641720 is a wasteful number, since it uses less digits than its factorization.

121641720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013695 (or 1013691 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 121641720 is about 11029.1305187671. The cubic root of 121641720 is about 495.4815841679.

Adding to 121641720 its reverse (27146121), we get a palindrome (148787841).

The spelling of 121641720 in words is "one hundred twenty-one million, six hundred forty-one thousand, seven hundred twenty".