121815490 has 16 divisors (see below), whose sum is σ = 219396600. Its totient is φ = 48697600.

The previous prime is 121815443. The next prime is 121815509. The reversal of 121815490 is 94518121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 62047129 + 59768361 = 7877^2 + 7731^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25836 + ... + 30184.

Almost surely, 2^121815490 is an apocalyptic number.

121815490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121815490 is a deficient number, since it is larger than the sum of its proper divisors (97581110).

121815490 is a wasteful number, since it uses less digits than its factorization.

121815490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7157.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 121815490 is about 11037.0054815607. The cubic root of 121815490 is about 495.7174102435.

It can be divided in two parts, 12181 and 5490, that added together give a palindrome (17671).

The spelling of 121815490 in words is "one hundred twenty-one million, eight hundred fifteen thousand, four hundred ninety".