121863558550 has 12 divisors (see below), whose sum is σ = 226666218996. Its totient is φ = 48745423400.

The previous prime is 121863558541. The next prime is 121863558559. The reversal of 121863558550 is 55855368121.

It is an interprime number because it is at equal distance from previous prime (121863558541) and next prime (121863558559).

It is a junction number, because it is equal to n+sod(n) for n = 121863558494 and 121863558503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121863558559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1218635536 + ... + 1218635635.

It is an arithmetic number, because the mean of its divisors is an integer number (18888851583).

Almost surely, 2^121863558550 is an apocalyptic number.

121863558550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121863558550 is a deficient number, since it is larger than the sum of its proper divisors (104802660446).

121863558550 is a wasteful number, since it uses less digits than its factorization.

121863558550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2437271183 (or 2437271178 counting only the distinct ones).

The product of its (nonzero) digits is 1440000, while the sum is 49.

The spelling of 121863558550 in words is "one hundred twenty-one billion, eight hundred sixty-three million, five hundred fifty-eight thousand, five hundred fifty".