1297999620 has 96 divisors (see below), whose sum is σ = 4056393600. Its totient is φ = 344575872.

The previous prime is 1297999601. The next prime is 1297999631. The reversal of 1297999620 is 269997921.

1297999620 is a `hidden beast` number, since 1 + 2 + 9 + 7 + 9 + 9 + 9 + 620 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 117286 + ... + 127874.

It is an arithmetic number, because the mean of its divisors is an integer number (42254100).

Almost surely, 2^1297999620 is an apocalyptic number.

1297999620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1297999620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2028196800).

1297999620 is an abundant number, since it is smaller than the sum of its proper divisors (2758393980).

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

1297999620 is a wasteful number, since it uses less digits than its factorization.

1297999620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10834 (or 10826 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The square root of 1297999620 is about 36027.7617955931. The cubic root of 1297999620 is about 1090.8328006877.

The spelling of 1297999620 in words is "one billion, two hundred ninety-seven million, nine hundred ninety-nine thousand, six hundred twenty".