1221776690 has 16 divisors (see below), whose sum is σ = 2199864960. Its totient is φ = 488562480.

The previous prime is 1221776687. The next prime is 1221776701. The reversal of 1221776690 is 966771221.

It is a super-2 number, since 2×1221776690² = 2985476560454712200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19895 + ... + 53285.

It is an arithmetic number, because the mean of its divisors is an integer number (137491560).

Almost surely, 2^1221776690 is an apocalyptic number.

1221776690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221776690 is a deficient number, since it is larger than the sum of its proper divisors (978088270).

1221776690 is a wasteful number, since it uses less digits than its factorization.

1221776690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37057.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 1221776690 is about 34953.9223836181. The cubic root of 1221776690 is about 1069.0481796735.

The spelling of 1221776690 in words is "one billion, two hundred twenty-one million, seven hundred seventy-six thousand, six hundred ninety".