1999913551 has 2 divisors, whose sum is σ = 1999913552. Its totient is φ = 1999913550.

The previous prime is 1999913537. The next prime is 1999913557. The reversal of 1999913551 is 1553199991.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1999913551 - 2¹¹ = 1999911503 is a prime.

It is a super-2 number, since 2×1999913551² = 7999308422946859202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999913557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999956775 + 999956776.

It is an arithmetic number, because the mean of its divisors is an integer number (999956776).

Almost surely, 2^1999913551 is an apocalyptic number.

1999913551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999913551 is an equidigital number, since it uses as much as digits as its factorization.

1999913551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 492075, while the sum is 52.

The square root of 1999913551 is about 44720.3930103482. The cubic root of 1999913551 is about 1259.9028964808.

The spelling of 1999913551 in words is "one billion, nine hundred ninety-nine million, nine hundred thirteen thousand, five hundred fifty-one".