139681840 has 20 divisors (see below), whose sum is σ = 324760464. Its totient is φ = 55872704.

The previous prime is 139681837. The next prime is 139681847. The reversal of 139681840 is 48186931.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×139681840² = 39022032851571200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 139681793 and 139681802.

It is not an unprimeable number, because it can be changed into a prime (139681847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 872932 + ... + 873091.

Almost surely, 2^139681840 is an apocalyptic number.

139681840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

139681840 is an abundant number, since it is smaller than the sum of its proper divisors (185078624).

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

139681840 is a wasteful number, since it uses less digits than its factorization.

139681840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1746036 (or 1746030 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 139681840 is about 11818.7072051050. The cubic root of 139681840 is about 518.8557680498.

The spelling of 139681840 in words is "one hundred thirty-nine million, six hundred eighty-one thousand, eight hundred forty".