121646640 has 40 divisors (see below), whose sum is σ = 377105328. Its totient is φ = 32439040.

The previous prime is 121646621. The next prime is 121646663. The reversal of 121646640 is 46646121.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 121646598 and 121646607.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 253191 + ... + 253670.

Almost surely, 2^121646640 is an apocalyptic number.

121646640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121646640 is an abundant number, since it is smaller than the sum of its proper divisors (255458688).

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

121646640 is a wasteful number, since it uses less digits than its factorization.

121646640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 506877 (or 506871 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 121646640 is about 11029.3535621994. The cubic root of 121646640 is about 495.4882642678.

The spelling of 121646640 in words is "one hundred twenty-one million, six hundred forty-six thousand, six hundred forty".