1221495500 has 48 divisors (see below), whose sum is σ = 2783761344. Its totient is φ = 467350400.

The previous prime is 1221495481. The next prime is 1221495521. The reversal of 1221495500 is 55941221.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

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, 41609 + ... + 64608.

It is an arithmetic number, because the mean of its divisors is an integer number (57995028).

Almost surely, 2^1221495500 is an apocalyptic number.

1221495500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221495500 is an abundant number, since it is smaller than the sum of its proper divisors (1562265844).

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

1221495500 is a wasteful number, since it uses less digits than its factorization.

1221495500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106259 (or 106247 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 1221495500 is about 34949.8998567950. The cubic root of 1221495500 is about 1068.9661601238.

The spelling of 1221495500 in words is "one billion, two hundred twenty-one million, four hundred ninety-five thousand, five hundred".