121781536 has 12 divisors (see below), whose sum is σ = 239757462. Its totient is φ = 60890752.

The previous prime is 121781533. The next prime is 121781537. The reversal of 121781536 is 635187121.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 97219600 + 24561936 = 9860^2 + 4956^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (121781533) by changing a digit.

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 as a sum of consecutive naturals, namely, 1902805 + ... + 1902868.

Almost surely, 2^121781536 is an apocalyptic number.

121781536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

121781536 is a deficient number, since it is larger than the sum of its proper divisors (117975926).

121781536 is an equidigital number, since it uses as much as digits as its factorization.

121781536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3805683 (or 3805675 counting only the distinct ones).

The product of its digits is 10080, while the sum is 34.

The square root of 121781536 is about 11035.4671853982. The cubic root of 121781536 is about 495.6713483592.

The spelling of 121781536 in words is "one hundred twenty-one million, seven hundred eighty-one thousand, five hundred thirty-six".