121551787620 has 48 divisors (see below), whose sum is σ = 378161118720. Its totient is φ = 32413809888.

The previous prime is 121551787603. The next prime is 121551787631. The reversal of 121551787620 is 26787155121.

121551787620 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 5 + 17 + 8 + 7 + 620 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112547412 + ... + 112548491.

It is an arithmetic number, because the mean of its divisors is an integer number (7878356640).

Almost surely, 2^121551787620 is an apocalyptic number.

121551787620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121551787620 is an abundant number, since it is smaller than the sum of its proper divisors (256609331100).

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

121551787620 is a wasteful number, since it uses less digits than its factorization.

121551787620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225095921 (or 225095913 counting only the distinct ones).

The product of its (nonzero) digits is 235200, while the sum is 45.

The spelling of 121551787620 in words is "one hundred twenty-one billion, five hundred fifty-one million, seven hundred eighty-seven thousand, six hundred twenty".