1951721004 has 12 divisors (see below), whose sum is σ = 4554015704. Its totient is φ = 650573664.

The previous prime is 1951720999. The next prime is 1951721039. The reversal of 1951721004 is 4001271591.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81321697 + ... + 81321720.

Almost surely, 2^1951721004 is an apocalyptic number.

It is an amenable number.

1951721004 is an abundant number, since it is smaller than the sum of its proper divisors (2602294700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1951721004 is a wasteful number, since it uses less digits than its factorization.

1951721004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162643424 (or 162643422 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 30.

The square root of 1951721004 is about 44178.2865670456. The cubic root of 1951721004 is about 1249.7004090553.

Adding to 1951721004 its reverse (4001271591), we get a palindrome (5952992595).

The spelling of 1951721004 in words is "one billion, nine hundred fifty-one million, seven hundred twenty-one thousand, four".