91015020 has 36 divisors (see below), whose sum is σ = 276079440. Its totient is φ = 24270624.

The previous prime is 91015019. The next prime is 91015027. The reversal of 91015020 is 2051019.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 91014984 and 91015002.

It is not an unprimeable number, because it can be changed into a prime (91015027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 252640 + ... + 252999.

Almost surely, 2^91015020 is an apocalyptic number.

91015020 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

91015020 is an abundant number, since it is smaller than the sum of its proper divisors (185064420).

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

91015020 is a wasteful number, since it uses less digits than its factorization.

91015020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505654 (or 505649 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 91015020 is about 9540.1792435991. The cubic root of 91015020 is about 449.8188900821.

Adding to 91015020 its reverse (2051019), we get a palindrome (93066039).

The spelling of 91015020 in words is "ninety-one million, fifteen thousand, twenty".