1990566451 has 8 divisors (see below), whose sum is σ = 2055360384. Its totient is φ = 1925808960.

The previous prime is 1990566443. The next prime is 1990566463. The reversal of 1990566451 is 1546650991.

It is a happy number.

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 1990566451 - 2³ = 1990566443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990566401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141885 + ... + 155281.

It is an arithmetic number, because the mean of its divisors is an integer number (256920048).

Almost surely, 2^1990566451 is an apocalyptic number.

1990566451 is a deficient number, since it is larger than the sum of its proper divisors (64793933).

1990566451 is a wasteful number, since it uses less digits than its factorization.

1990566451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18221.

The product of its (nonzero) digits is 291600, while the sum is 46.

The square root of 1990566451 is about 44615.7646017638. The cubic root of 1990566451 is about 1257.9370060282.

The spelling of 1990566451 in words is "one billion, nine hundred ninety million, five hundred sixty-six thousand, four hundred fifty-one".