1556143990 has 16 divisors (see below), whose sum is σ = 2814338160. Its totient is φ = 619506720.

The previous prime is 1556143987. The next prime is 1556144003. The reversal of 1556143990 is 993416551.

It is a super-2 number, since 2×1556143990² = 4843168235226240200, which contains 22 as substring.

It is a congruent number.

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, 366645 + ... + 370864.

It is an arithmetic number, because the mean of its divisors is an integer number (175896135).

Almost surely, 2^1556143990 is an apocalyptic number.

1556143990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1556143990 is a deficient number, since it is larger than the sum of its proper divisors (1258194170).

1556143990 is a wasteful number, since it uses less digits than its factorization.

1556143990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 737727.

The product of its (nonzero) digits is 145800, while the sum is 43.

The square root of 1556143990 is about 39447.9909501105. The cubic root of 1556143990 is about 1158.8216308633.

The spelling of 1556143990 in words is "one billion, five hundred fifty-six million, one hundred forty-three thousand, nine hundred ninety".