121978455 has 32 divisors (see below), whose sum is σ = 201427968. Its totient is φ = 62985600.

The previous prime is 121978427. The next prime is 121978457. The reversal of 121978455 is 554879121.

It is not a de Polignac number, because 121978455 - 2¹⁶ = 121912919 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121978457) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 150000 + ... + 150810.

It is an arithmetic number, because the mean of its divisors is an integer number (6294624).

Almost surely, 2^121978455 is an apocalyptic number.

121978455 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121978455 is a deficient number, since it is larger than the sum of its proper divisors (79449513).

121978455 is a wasteful number, since it uses less digits than its factorization.

121978455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1127.

The product of its digits is 100800, while the sum is 42.

The square root of 121978455 is about 11044.3856778003. The cubic root of 121978455 is about 495.9383689790.

The spelling of 121978455 in words is "one hundred twenty-one million, nine hundred seventy-eight thousand, four hundred fifty-five".