121601664 has 48 divisors (see below), whose sum is σ = 349924770. Its totient is φ = 40533504.

The previous prime is 121601657. The next prime is 121601693. The reversal of 121601664 is 466106121.

It can be written as a sum of positive squares in only one way, i.e., 94478400 + 27123264 = 9720^2 + 5208^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 51627 + ... + 53930.

Almost surely, 2^121601664 is an apocalyptic number.

It is an amenable number.

121601664 is an abundant number, since it is smaller than the sum of its proper divisors (228323106).

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

121601664 is a wasteful number, since it uses less digits than its factorization.

121601664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105577 (or 105562 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 121601664 is about 11027.3144509441. The cubic root of 121601664 is about 495.4271916748.

Adding to 121601664 its reverse (466106121), we get a palindrome (587707785).

It can be divided in two parts, 121601 and 664, that added together give a triangular number (122265 = T₄₉₄).

The spelling of 121601664 in words is "one hundred twenty-one million, six hundred one thousand, six hundred sixty-four".