1990551155 has 8 divisors (see below), whose sum is σ = 2471029200. Its totient is φ = 1537529056.

The previous prime is 1990551149. The next prime is 1990551163. The reversal of 1990551155 is 5511550991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1990551155 - 2⁴ = 1990551139 is a prime.

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, 6863825 + ... + 6864114.

It is an arithmetic number, because the mean of its divisors is an integer number (308878650).

Almost surely, 2^1990551155 is an apocalyptic number.

1990551155 is a deficient number, since it is larger than the sum of its proper divisors (480478045).

1990551155 is a wasteful number, since it uses less digits than its factorization.

1990551155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13727973.

The product of its (nonzero) digits is 50625, while the sum is 41.

The square root of 1990551155 is about 44615.5931822048. The cubic root of 1990551155 is about 1257.9337839213.

The spelling of 1990551155 in words is "one billion, nine hundred ninety million, five hundred fifty-one thousand, one hundred fifty-five".