1690631990 has 16 divisors (see below), whose sum is σ = 3047971680. Its totient is φ = 675178560.

The previous prime is 1690631977. The next prime is 1690632017. The reversal of 1690631990 is 991360961.

It is a happy number.

It is a super-2 number, since 2×1690631990² = 5716473051222720200, 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, 127655 + ... + 140274.

It is an arithmetic number, because the mean of its divisors is an integer number (190498230).

Almost surely, 2^1690631990 is an apocalyptic number.

1690631990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1690631990 is a deficient number, since it is larger than the sum of its proper divisors (1357339690).

1690631990 is a wasteful number, since it uses less digits than its factorization.

1690631990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268567.

The product of its (nonzero) digits is 78732, while the sum is 44.

The square root of 1690631990 is about 41117.2955093109. The cubic root of 1690631990 is about 1191.2868855033.

The spelling of 1690631990 in words is "one billion, six hundred ninety million, six hundred thirty-one thousand, nine hundred ninety".