1398507681 has 16 divisors (see below), whose sum is σ = 1925907968. Its totient is φ = 901756800.

The previous prime is 1398507667. The next prime is 1398507697. The reversal of 1398507681 is 1867058931.

It is not a de Polignac number, because 1398507681 - 2¹⁹ = 1397983393 is a prime.

It is a super-2 number, since 2×1398507681² = 3911647467631995522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1398507681.

It is not an unprimeable number, because it can be changed into a prime (1398507631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234861 + ... + 240741.

It is an arithmetic number, because the mean of its divisors is an integer number (120369248).

Almost surely, 2^1398507681 is an apocalyptic number.

It is an amenable number.

1398507681 is a deficient number, since it is larger than the sum of its proper divisors (527400287).

1398507681 is a wasteful number, since it uses less digits than its factorization.

1398507681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8472.

The product of its (nonzero) digits is 362880, while the sum is 48.

The square root of 1398507681 is about 37396.6265992001. The cubic root of 1398507681 is about 1118.2913148693.

The spelling of 1398507681 in words is "one billion, three hundred ninety-eight million, five hundred seven thousand, six hundred eighty-one".