91220070 has 64 divisors (see below), whose sum is σ = 231704064. Its totient is φ = 22936320.

The previous prime is 91220057. The next prime is 91220117. The reversal of 91220070 is 7002219.

It is a happy number.

It is a super-2 number, since 2×91220070² = 16642202341609800, which contains 22 as substring.

It is a congruent number.

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, 49465 + ... + 51275.

It is an arithmetic number, because the mean of its divisors is an integer number (3620376).

Almost surely, 2^91220070 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91220070, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115852032).

91220070 is an abundant number, since it is smaller than the sum of its proper divisors (140483994).

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

91220070 is a wasteful number, since it uses less digits than its factorization.

91220070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1917.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 91220070 is about 9550.9198509882. The cubic root of 91220070 is about 450.1564394358.

Adding to 91220070 its reverse (7002219), we get a palindrome (98222289).

The spelling of 91220070 in words is "ninety-one million, two hundred twenty thousand, seventy".