121649 has 4 divisors (see below), whose sum is σ = 132720. Its totient is φ = 110580.

The previous prime is 121637. The next prime is 121661. The reversal of 121649 is 946121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 946121 = 11 ⋅86011.

It is an interprime number because it is at equal distance from previous prime (121637) and next prime (121661).

It is a cyclic number.

It is not a de Polignac number, because 121649 - 2⁴ = 121633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5519 + ... + 5540.

It is an arithmetic number, because the mean of its divisors is an integer number (33180).

2¹²¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

121649 is a deficient number, since it is larger than the sum of its proper divisors (11071).

121649 is a wasteful number, since it uses less digits than its factorization.

121649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11070.

The product of its digits is 432, while the sum is 23.

The square root of 121649 is about 348.7821669753. The cubic root of 121649 is about 49.5491468479.

It can be divided in two parts, 12 and 1649, that added together give a palindrome (1661).

The spelling of 121649 in words is "one hundred twenty-one thousand, six hundred forty-nine".